Unearth the Potential of the Voumard CNC 300 Machine

In the Reman weekly blog series, we provide a thorough explanation of the rotating precision grinding machines, specifically their application focusing on Voumard CNC 300 Grinding Machine. Being a machinery expert, I shall try to make you understand the Voumard CNC 300 as to why it has suited Voumard’s innovations and other vertical technology. Readers are given the relevance of Voumard technology and advancements in CNC technology, and the required degree of precision and accurateness achieved in grinding processes. These ideas highlight the impact and applicability of this astonishing machine. Let us dig into the features of the Voumard CNC 300 and its payoffs with respect to the grinding machining industry in general.

What sets the Voumard CNC 300 in a class of its own in the machinery space?

What sets the Voumard CNC 300 in a class of its own in the machinery space?
Picture source:https://www.theengineerspost.com/

With the level of precision that Voumard CNC 300 is able to maintain and incorporate into its tools, the cutting edge CNC technology and considerable grinding capabilities it is not a wonder that Voumard CNC 300 is one of the leading options in this space. Industrial machines of this caliber are equipped with modern innovative design to maximize productivity. The edge that is enjoyed by Voumard CNC 300 is in its delivery of grinding operations. This not only ensures great results but offers a variety of services as well. Spindles are one of the important parts of the machine, and turret optimization also does wonders in enhancing the output of the machine. Specialized as it is in external and OD grinding, the Voumard CNC 300 allows for diverse and specific applications without compromising quality. In regards to other CNC grinding machines the Voumard 300 core traits remain unmatched. Voumard CNC 300 enables us to move past conventional technology and enter an age of unparalleled precision and accuracy.

Grasping the Voumard Advantage

The claim can be made that the Voumard CNC 300 is fully equipped and incorporates several features and improvements that enhance performance during grinding. Let’s bring a few details, data that tell about its advantages.

  • Remarkable Type CNC: The Voumard CNC 300 applies advanced technologies in CNC, which allows for structural control of the grinding operations being performed. This technology, in turn, allows us to achieve high productivity while minimizing errors.
  • High-Fidelity Spindle: The spindle of Voumard 300 Series is vital in successful completion of precision grinding. It has excellent rigidity and stability delivering outstanding rotational accuracy, thus, reducing vibrations and enhancing grinding achievable results.
  • Optimized Turret configuration: Voumard CNC 300 is made with a turret configuration that has been optimized to enhance performance while grinding key components. This makes it easy and quicker to change and use different tools shortening the change over periods.

Voumard 300 has the ability to execute high OD & External grinding The Voumard CNC 300 as the name suggests can perform external and OD grinding which enables it perform well within the specifications of many applications. All of its features in these respects allow it to best surface finish, while maintaining tight tolerances.

When considering the Voumard CNC 300 against other grinding machines, it is clear that this machine distinguishes itself as the machine of choice. It’s technology and the level of detail excellence it holds brings about an industry shift. The Voumard CNC 300 promises nothing short of high-quality grinding across numerous areas of machining.

The Voumard CNC 300 grinding machine is worth noting as a mark of an industry change; however, one has to appreciate the growth of other techniques which in this case is crucial to CNC(Computer Numerical Control) innovation.

There are numerous areas of CNC that increase the performance of a machine including its stiffness or worst-case scenario requirements and with the Voumard CNC 300 these are well taken care of. Because of the multiplicity of the g_img and g_img_asm it is possible to achieve the greatest level of precision and accuracy, surface finish and dimensions in grinding. In this regard, let us start explaining some essential details to understand the reasons behind the machine’s excellent quality.

1. Accuracy gained through Spindle Technology:

Grinding operations from the onset require the spindle for precision to be achieved. The Voumard CNC 300 improves spindle technology, which significantly reduces vibrations and increases stability during grinding processes. As a result, even the most complicated workpieces give better accuracy and surface finishing.

2. Highly Efficient Turret:

Productivity and precision in grinding applications is highly dependable on turret operation. Voumard CNC 300 has been equipped with new turret design and controls that enhance the tool positioning, tool changing time and general efficiency of grinding to the maximum. This makes it possible to easily perform accurate and repeatable grinding operations on complicated structures.

3. Outside diameter grinding and External Grinding:

The Voumard CNC 300 provides advanced features of external grinding and OD (Outside Diameter) grinding. This allows the machine to cater a wide range of workpieces in terms of their shapes, sizes and materials. The vast flexibility and adaptability of the machine makes it fit for industries like automotive, aerospace, or medical in which precise grinding is a necessity.

When Voumard CNC 300 is placed on comparison with other grinding machines on the market, its distinguishing features and capabilities gives it’s users a true sense of touch that it has something unique. Never have I seen a machine that is fail proof or inaccurate even once, but for the Voumard CNC 300, that wouldn’t be a surprise because of how well it was built to maintain precision.

In order to fully utilize the advantages offered by the Voumard CNC 300, it makes use of Siemens 840D CNC system’s full functionality. This powerful controller has wide range of programming, governing of the machine’s motions and controlling of the grinding operation in a given timeframe. With the Siemens 840D CNC retrofitted to the system, conformance and modification becomes easy allowing the grinding activities to be effective and efficient.

As a result, it can be argued that the Voumard CNC 300 is an evolution in the field of CNC grinding machines, It is able to achieve grinding results that are of premium quality and its features and performance can just be emphatically termed as a multi-tasker and so its not surprising that industries that would prefer high-quality grinding results will opt for the otherwise latest from Voumard CNC 300 which taps on the latest developments in the field of CNC machines.

Turning Performance Requirements into Attributes in Grinding Machine

Apart from the main advantage of high performance output, Voumard CNC 300 also incorporates features and application of the latest technology. Below are important facts and figures supporting its characteristics and accomplishments:

High power spindle – Voumard CNC 300 has a high-speed spindle which allows for accuracy and quiet grinding operations to take place. The electric motors and heavy duty bearings are accurately constructed to reduce vibrations which therefore enhances surface smoothening as well as aids in proper geometry of parts being worked upon.

  • Turret Efficiency Optimization: The turret system of the machine is built in such a manner as to maximize efficiency of the machine by improving quick tool changes and reducing the time required for setup. The indexing precision of the turret allows the machine to have multiple grinding operations with a single setup which maximizes outputs.
  • External Grinding and OD Grinding: The Voumard CNC 300 is particularly good at external grinding and OD (Outer Diameter) grinding tasks. Its such structure design permits it to work on both internally and externally large workpieces of smaller intricate parts while ensuring concentricity and dimensional accuracy.
  • Comparative Analysis: In the first metric, the Voumard CNC 300 is tested with a few other grinding machines to find any possible features that are different, and a few were noticeable. The Voumard CNC 300 was found to have a 300 mm capacity which enables it to grind bigger workpieces effectively with high precision. Moreover, the capabilities of the Siemens 840D CNC system are fully engaged by the machine which allows it to function perfectly.
  • Importance of the B Axis: The significance of the B axis in CNC grinders such as Voumard CNC 300 is very vital. It rotates the grinding wheel around the X-axis allowing for tapers and grinders to change non-circular and complex contours during work with high precision and in multiple repetitions.

Such details and data demonstrate the wonder of Voumard CNC 300 and the benefits it presents in precision grinding operations. On the basis of the performance and technical sophistication, it is possible for the industries to obtain better results in grinding operations and upgrade their output performance.

How Does the Voumard CNC 300 Deliver Precision in Grinding Operations?

How Does the Voumard CNC 300 Deliver Precision in Grinding Operations?

The Significance of the Spindle in the Attainment of Precision

It is the time and the vreme vulnerabilities and weaknesses in a structure which can have direct bearing on elastic properties

Efficiency Features and Technical Perfection of Voumard CNC 300

Spindle, Its Part In Attaining The Target

Increasing the Output of a Turret by Widening the Power

New movements in the scope of external grinding and OD grinding processes

A comparative analysis of Voumard VM 300 and other grinding machines in different areas of their application.

Differences between the models of Voumard and their significance

The advantages of a work spindle which has a capacity of 300 mm

Siemens 840D CNC Complete Package Solution

Analysis of the role of the B axis in CNC grinders.

Understanding the interface between manual and automatic control in the processes of grinding.

Improving the properties of the grinding wheel.

Improving the Efficiency of the Turret

In addition to this it is understanding the prime objective of the use of imaging and imaging technologies. The following points are worth considering to enhance turret performance:

Tooling: Select suitable cutting tools in terms of required machining and material processes. Optimization of geometry, coatings and verification of tool reliability can be done to achieve longer tool life.

Tool Management System: A well-organized system for locating, securing, and tracking tools with the help of sophisticated software systems for monitoring use, tool life, and periodic replacement or maintenance.

Cutting Parameters Optimization: Determination and adjustment of cutting parameters such as cutting speed, feed rate, and depth of cut with the aim of improving operation. Getting the most output while taking care of tool lifespan and quality of the workpiece.

Automation and Robotics: Employ automation and robotics to replace human efforts in performing turret operations to increase efficiency. Improved productivity could be gained by automated tooling, work piece manipulation, and monitoring the process.

Real-Time Monitoring and Analytics: Implement modern monitoring and analytics tools to collect data about the turret in action and examine it to seek for any possible improvement, optimization of processes as well as elimination of possible malfunctions in the future.

Continuous Training and Skill Development: Create and implement training programs for pilots of turrets to broaden their skills and knowledge. Keep on improving in the area of turret technology, tooling and machining so as to find new areas where efficiencies could be realized.

Manufacturers can focus on enhancing turret performance, mitigating delays, maximizing output and making more money in their businesses by way of employing the strategies above and harnessing the new technologies.

Engaging With External Grinding and OD Grinding

A machine such as the Voumard VM 300 has some considerations that involve some performance indicators and some specifications that if assessed properly can lead to making good investments. These additional details and facts about the efficiency and possibilities of this machine give us information.

Grinding Capacity: The Voumard VM 300 allows a 300 a fair amount which evokes great imagination to the type and the size of workpieces and applications to be deployed using this machine.

Control System: With the Siemens 840D CNC control, this grinding machine has the desired level of accuracy and versatility. This can be attributed to the advanced control nature of the machine whereby accurate adjustments and programming changes can be made.

B Axis Functionality: The introduction of B axis in CNC grinders like the Voumard VM 300 is essential if one is to achieve greater accuracy and flexibility during grinding operations. In effect, it allows the grinding wheel head to swivel, which allows one to grind at multiangled locations and the complex geometries of the workpiece to be addressed.

Manual and Automatic Control: It is also important to know the available control options maybe all of them relevant. The Voumard VM 300 has both manual control and automatic control modes which enables the operators to select the best option according to the preset conditions of grinding.

Grinding Wheel Performance becomes one of the primaries areas of concern when one has to get the desired results. Advanced technologies and tooling techniques utilized in the Voumard VM 300 are aimed at increasing the effectiveness of the grinding wheel, thereby improving the surface finish and achieving the required dimensions.

That said, it is important to take the time of closely examining these details and data when going for the Voumard CNC 300 or any grinding machine as it allows you to make a sound decision. Choosing right machine with the necessary performance metrics and specifications improved the grinding works and improves efficiency and profitability aspects of operations.

Comparing the Voumard VM 300 with Other Grinding Machines?

Comparing the Voumard VM 300 with Other Grinding Machines?

Analyzing the differences between the Voumard variants

While trying to find the most favorable deal for the acquisition of Voumard CNC 300, it is suggested to go through the first few pages of Google Search in attempts to locate such deals. This is because these websites usually have many alternatives to buying the Voumard CNC 300 such as second hand machines. In this way you are able to compare prices and the status and reliability of the sellers to make an informed and cheap purchase. Also, other things like warranty, after sale service, and other benefits compulsory /optional services offered by the sellers should be considered. Therefore, with adequate information and homework, you are able to get the best price for purchasing a Voumard CNC 300 in accordance with your requirements and financial circumstances.

Merits of the 300 mm Capacity

Informed by the most recent information coming from Google, the price research work of Voumard CNC 300 is now much easier as the logs search menu enables individuals to search for websites on Google Search Placing Boards regularly. These sites have a variety of types including used and new ones that can be suited to your personal requirements and financial capabilities. In doing so, it is recommended to take into account their reputation, its credibility, warranty, after-sales service and other services rendered. Step by step the risk in buying the Voumard CNC 300 is minimized when price and reliability are made as a base for purchasing the goods.

Grasping Manual and Automatic Control

In case of CNC grinders, the requirement of a B Axis is that it can be controlled manually as well as automatically depending on the time parameters set in a grinding process. Manually, the position of the grinding wheel is set through the use of say a hand wheel or joystick. Alternatively, automatic systems set and control the position of B Axis as per the programmed parameters using computerized systems which enhances the B Axis capabilities of grinding Rigidly.

Taking Grinding Wheel Efficiency to another Level

The ability to adjust the B Axis has a significant effect on the performance characteristics of the grinding wheel. The operators change the angle and the orientation of the wheel with respect to the workpiece so that the best possible removal, surface finish and dimensional performance is achieved. This feature makes it possible to grind intricate shapes, angular features and contoured surfaces very efficiently.

Where to Get the Best Price for a Voumard CNC 300?

Where to Get the Best Price for a Voumard CNC 300?

Advantages of Buying CNC Machines

First, ask friends and acquaintances to recommend reliable web pages or online platforms that specialize in selling CNC machines. Most pages that deal with such business provide a wide range of services, both for new and used Voumard’s CNC 300. Therefore, do not be in a rush to compare the first two options you get, always take time to check all the possible deals, and look for ways to save money.

Introduction to Manual And Automatic Control

When discussing the optimization of the Voumard’s CNC 300 grinding wheel performance in a CNC grinder, many aspects are to be considered. As stated earlier, considerable improvement in both efficiency in grinding and surface characteristics can be achieved through effective application of skilled techniques and technologies. The following are some essential factors that must be taken into account for enhancing the performance of a grinding wheel:

Selection Of Grinding Wheel: Different applications require different abrasive material, grain size and bonding system. Doing this is straightforward using Voumard’s specifications and guidance on particular materials and workpiece materials ensuring accurate results are achieved.

Wheel Dressing and Truing: The sharpening of the cutting edges of the grains occurs during the dressing and truing procedures of the grinding wheel. These two procedures are necessary for the cutting edge of the grinding wheel to remain sharp, be well-defined, and attain the desired dimensions.

Coolant and Lubrication: It is vital to utilize these systems in normal operation their presence ensures effective heat control during each grinding operation. Such tools help in preventing overheating and heat destruction of the workpiece and the grinding wheel.

Feed Rate and Depth of Cut: Maximizing the material removal rate and minimizing wheel wear can be attained by regulating the feed rate and depth of cut. However, it is necessary to flood every parameter for proper dimensional accuracy and surface finish before hard machining.

Monitoring and Control: Cutting-edge monitoring systems may enable evaluation of the grinding process in real time. Continuous monitoring of grinding forces, temperature, and power consumption as parameters of wheel performance through and after grinding cycles can help in its maintenance and optimal grinding conditions.

Manufacturers can improve efficiency, accuracy and durability of their grinding wheels, hence adhering to the general increase of their productivity and consonantly the quality of the products.

Improving the Performance of the Grinding Wheel

Aiming for optimal grinding wheel performance, going through many things and collecting the data is a must. It is through these certain details and metrics that it will allow the manufacturers to be able to make decisions over their grinding processes. Specific details and data that could be useful in enhancing grinding wheel performance are as follows:

  • Surface Roughness Measurements: The use of surface roughness measurement tools with high accuracy surface sensors for the evaluation of finishes achieved on the product. This information is useful to determine the capability of the grinding wheel and simply how or what adjustments are made to achieve the required surface texture.
  • Material Removal Rate (MRR): The rate of material removed per unit time regarding the Grinding process and its volume can provide other mechanics related to the wheel’s behaviour or assist in the optimization of the parameters to grind with the wheel.
  • Power Consumption Monitoring: Recording the power consumed throughout the process can give a sound assessment of the energy efficiency of the operation. The working or the energy graphs can be used in detecting any unusual abnormalities or leaks which can later be adjusted to save on power.
  • Grinding Wheel Wear Analysis: The degrading condition of the grinding wheel ought to be checked on a periodic basis so as to allow for any form of maintenance when necessary. This will also allow for monitoring of the wheel’s status to determine the right time for re-dressing or replacing it whenever there exists a cut down on performance in order to be able to cope with the minimal downtime of operations.
  • Process Monitoring Software: The incorporation of specific process monitoring programs allows for the capture and examination of real-time data from the different sensors and monitoring systems. Such software allows a thorough assessment of fundamental aspects like nominal and actual values of grinding forces, temperatures and wheel usage within a particular cycle during which valuable information about a certain type of grinding is gathered.

With the inclusion of these parameters and data driven models building the grinding process, the manufacturers will be able to determine components like parameters and to improve the performance of their grinding wheels leading to increased efficacy and quality of the finished product.

Where to Get the Best Price for a Voumard CNC 300?

Where to Get the Best Price for a Voumard CNC 300?

Exploring Options for Machines for Sale

While looking for a Outward CNC 300, it is rather careful in watching different aspects, so as to ensure an informed buying decision. Some of the important aspects which should be taken into consideration are:

Machine Details: Check the Outward CNC 300’s machine details particularly the dimensions, weight and machining specification matrix. Such knowledge would assist you in deciding whether the machine is suit able for your specific needs as well as production requirements.

Condition and Maintenance: Check the general state of the machine and its maintenance record, the information that is required pertain to how the machine was serviced for example how many and what type of repairs, upgrades or replacement’s undertaking.

Control System: What type of control system is used in the Voumard CNC 300 for the unit must be known in this case in order to ensure that the control system is effective and easy to use.

Tooling and Accessories: More important the machine has tooling and accessories collets, grinding wheels, dressing tools, and any other items that would be needed to make the machine operational, and ensures to check possible availability.

Service and Support: Explore the service and support options for the Voumard CNC 300. Determine whether the women’s health products manufacturer or any endorsed service provider ensures repair, supply of goods, and parts for proper function and assurance reliability of the Voumard CNC 300.

Price and Financing Options: Take into consideration the cost of Voumard CNC 300, and if it is applicable, check for any financing alternatives. One should shop around with other credible retailers and use the pricing with other factors such as wear, dimensions, and special aspects of the machine.

You should be able to evaluate these factors and obtain a reasonable conclusion, proceed and buy most appropriate Voumard CNC 300 suitable for your machining needs and the overall giving worth to your enterprise over the time.

How to Look for Offers on Voumard CNC 300 Deals

To be able to properly evaluate the offers on the Voumard CNC 300, one must take into consideration the different factors while assessing the tools. With Voumard CNC Voumard on the rise it is critical to have fragment with such details to assist you in making effective and quick decisions.

  • 1. Machine Condition and Performance: While buying a Voumard CNC 300 machine, inquire about the performance and working history of the machine, its effectiveness, and any issues experienced by other users. While buying Ensure that the commissioning specifications and features such as precision, speed, and degree of containment are adequate for your intended machining application.
  • 2. Tooling and Accessories: Find out whether the machine comes with suitable maintenance tools, such as collets, grinding wheels, or dressing tools. Confirm that the additional tools are in good working order and that they are adequate for your purposes.
  • 3. Service and Support: Look into what service and support the manufactuer offers for Voumard CNC 300. Explain if midnified maintenance, technical support, and replacement will be provided to further the effectiveuse of the machine. Having reliable service and support at a reasonable cost could cut down time spent in idleness while improving levels mrp.
  • 4. Price and Financing Options: First and foremost, investigate the pricing for the Voumard CNC 300, together with the possible options for payment. It is extremely necessary to look for competitive quotes by different credible dealers and analyze the worth of the machine as per its range of usage, features and working conditions. With such an estimation of a price, also include some other factors such as the costs of transporting the machine or payments for its installation.

You can obtain relevant and updated information needed for finding the right Voumard CNC 300 that would suit your specified machining tasks by thoroughly examining all these aspects and searching for relevant information on Google.

Frequently Asked Questions (FAQs)

Frequently Asked Questions (FAQs)

Q: What are the key features of the Voumard CNC 300 machine?

A: The Voumard CNC 300 machine features precise grinding of internal, external, and face diameters as well as internal taper cross sections. It has a Siemens 840D CNC control and has all the necessary features required for complicated machining operators.

Q: How does the B axis enhance the capabilities of the Voumard CNC 300?

A: The addition of the B axis in the Voumard CNC 300 makes it possible to machine complicated shapes with greater ease especially when finishing multiple surfaces like the front and back faces together with internal tapers and external diameters.

Q: What role does the Siemens 840D CNC control play in the Voumard CNC 300?

A: Siemens 840D CNC control is one of the most essential features of theVoumard CNC 300 as it improves the operations range of the machine. The control system achieves high efficiency during machining operations while ensuring full dimensional accuracy of parts manufactured.

Q: Do the users need to download separate Voumard CNC 300 manuals?

A: Not necessary. Manuals are also part of the package in the Voumard CNC 300 machine. These manuals explain some advanced features of the Siemens 840D CNC so that the potential of the machine’s grinding functions can be fully utilized.

Q: What kind of parts can be manufactured in the full range on the Voumard CNC 300?

A: The Voumard CNC 300, being fully functional, can manufacture parts that include, but not limited to, those that have prismatic internal diameters, outer diameter, and plunge as well as face ends that are quite complex.

Q: How does Voumard CNC 300 guarantee some level of accuracy in machining processes?

A: A strong structure, Siemens 840D CNC control, and the ability to do a range of grinding works that encompass internal tapers and singular geometries on both the front and back of the faces ensure precision.

Q: What are the pros in employing the Voumard CNC 300 in grinding operations?

A: The Voumard CNC 300 is said to have high accuracy of dimensions and a wide scope of use in terms of shapes and sizes and the efficiency gotten from Siemens 840D CNC control which has a degree in making good operating parts.

Q: Is it possible to perform both internal and external grinding using the Voumard CNC 300?

A: It is possible, in fact, the Voumard CNC 300 performs sesamoid internal and external grinding where its design enables cutting of an internal diameter along with external diameter and different surface geometries.

Q: Can this machine be relied upon in creating components of great quality?

A: Yes, without doubt, the Voumard CNC 300 comes powerful in creating components of great quality. All parts including many internal tapers and numerous external surfaces are functional and are made under the supervision of Siemens 840D CNC control.

Reference Sources

  1. “A Customizable Controller for 3 Axis Modular CNC Machine” by Jagathesvaran Veeramony and Muhammed Nafis Osman Zahid (2022):
    • Key Findings: This study presents a customizable controller for a three-axis CNC machine using an Arduino Uno board. The research highlights the potential for low-cost CNC solutions that can be adapted for various applications.
    • Methodologies: The authors utilized an Arduino microcontroller to control stepper motors and developed a system that allows users to convert images or text files into G-code for CNC operations. The study emphasizes the importance of open-source technology in making CNC machining more accessible(Veeramony & Zahid, 2022).
  2. “CNC router selection for SMEs in woodwork manufacturing using hesitant fuzzy AHP method” by Alper Camci et al. (2018):
    • Key Findings: This paper discusses the selection criteria for CNC routers in small and medium-sized enterprises (SMEs) in the woodwork industry, emphasizing the importance of technical aspects over economic factors.
    • Methodologies: The study employs a hesitant fuzzy analytic hierarchy process (HFAHP) to evaluate and prioritize selection criteria for CNC routers, providing a structured decision-making framework for SMEs(Camci et al., 2018, pp. 529–549).
  3. “Digitalization of The Construction Industry with BIM and 3D Machine Control Integration for Construction Performance Improvement” by Iwan Hermawan and Sutardi Sudirman (2023):
    • Key Findings: This research explores the integration of Building Information Modeling (BIM) with 3D machine control to enhance construction performance, which can be relevant for CNC applications in construction.
    • Methodologies: The study involved field experiments to assess the accuracy of topographic data and the efficiency of 3D machine control in construction projects(Hermawan & Sudirman, 2023).

Numerical control

Cam (mechanism)

Categorization of our articles
UDPEDIAS

UDPEDIAS is dedicated to creating content that is relevant and valuable to users so that it is safe to start content on this encyclopedic life he takes into account all known encyclopedias, we believe you will like our content!

 

You may be interested in
guar gum ionic or covalent

The Overlooked Potential of Guar Gum: A Review of Its Rheology and Synergetic Effects Guar

Learn More →
243 Park Avenue in New York City Office Markets: A More Complex Analysis
243 Park Avenue in New York City Office Markets: A More Complex Analysis

245 Park Avenue is one of the many buildings that contribute to New York City’s

Learn More →
What is Stracciatella Ice Cream
Discover the Delight of Stracciatella Ice Cream: The Ultimate Gelato Experience

This delicacy sweet frost dish has high demand among gelato lovers across the globe. Stracciatella

Learn More →
Scroll to Top
Get in touch with UDPEDIAS company

Kindly complete the form below to reach out to us. We aim to get back to you within 12 hours. Best of luck!

Contact Form 在用