JPS62136368A - Tool balancing device - Google Patents

Abstract

PURPOSE:To curtail time for balancing work by providing a static pressure bearing in the cylinder of a device body and and a hooking member for contacting the center of a tool support axis from the back in a balancing device for tools to be mounted on the spindle of a machine tool. CONSTITUTION:Pressurized air is fed from an air feed hole 5 and jetted toward a static pressure bearing space 24. For the air flowing toward a secondary cylinder 3, a flange part 9 is energized aft to get in contact with the projected tip of a hooking member 11. Therefore, a support axis 10 can rotate in a completely afloat condition. And balancing work for a grindstone 8 is done in such a way that the grindstone 8 is first adjusted to be level in an axial direction and then mounted on the support axis 10 to obtain the direction of the center of gravity thereof and fit balancing pieces 35, 36 and 37. In the subject device, the tool support axis 10 is in non-contact with a bearing and the smooth rotation thereof is ensured, thereby enabling short-time proper balancing work for tools.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device used for balancing various tools attached to a spindle of a machine tool such as a grinder, which rotates at high speed.

2. Description of the Related Art In various tools attached to this type of high-speed rotating spindle, if the center of gravity of the tool is not located at the center but somewhere from the center, imbalance occurs.

If this imbalance causes the tool to rotate at high speed,
This may cause mechanical vibration or centrifugal breakage of the tool. Among them, the grinding wheels used in grinding machines are particularly hard and brittle, so even if the grinding wheels do not break centrifugally, the vibrations of the machine will cause the grinding wheels to violently collide with the workpiece. , the wear of the grindstone is significant, and the finished surface of the workpiece is also deteriorated. Therefore, during grinding work, it is necessary to make corrections to minimize the imbalance of the grindstone. In other words, it is necessary to strike a balance.

Conventionally, this type of tool balancing has generally been achieved by using a parallel flange type balance table a as shown in FIG. 6, for example.

In this method, both ends of a mandrel d inserted into the center of a tool, such as a grinding wheel C, are placed on two horizontal flanges b that are parallel to each other, with the frame passing between the two flanges 5, and from this state the grinding wheel is Find the center of gravity of the whetstone C by looking at the rotating direction and resting angle of the whetstone C, and use two or three balance pieces e to attach it to the annular groove formed on one end surface of the whetstone C and adjust its arrangement. Whetstone C balance 7F! : It was designed to be taken.

However, in this method, the movement of the grinding wheel C is observed as the central mandrel d rolls on the two flanges b while contacting them, so there may be rust, scratches, or scratches on the surface of the mandrel 6 or the flange 5. If there is any deposit, the grinding wheel C will not be able to rotate smoothly. For this reason, it is difficult for the operator to find the center of gravity of the grindstone C, making balancing work extremely difficult.

In many cases, this type of tool balancing work is performed in a factory where there is a lot of dirt and dust in the air, so the exposed flange b surface is easily contaminated and rusts easily, so both surfaces are always checked. It was necessary to clean the surface and repair any scratches to maintain the surface accuracy.

In addition, the left and right flanges 5 on which both ends of the mandrel d are placed
In addition to the horizontal adjustment between the two, it is also essential to horizontally adjust the length of the flange B. Therefore, at least two horizontal adjustment screws f are required on the bottom of the balance table a, and the installation location of the balance table a is also required. The selection of the balance table a and the leveling work of the balance table a were extremely troublesome and time-consuming.

Furthermore, since the grindstone C is not in a fixed position but moves in either direction while rolling along the flange b, the worker has to repeatedly return the grindstone C to the center position and gently place it again. It had many drawbacks, such as requiring a lot of work and taking a lot of time to balance.

Therefore, these defects directly affect the balancing accuracy and prevent the grinding wheel C from being perfectly balanced.As a result, the grinding wheel C may vibrate on the machine side, or the grinding wheel C may go to one side, causing the roundness of the grinding wheel C itself to deteriorate. This caused chattering marks to appear on the surface of the workpiece, resulting in poor finished surfaces.

Object of the Invention and Means for Solving the Problem In other words, the object of the present invention is to floatingly support a tool spindle holding a tool at one end so that it can rotate freely using a hydrostatic bearing. The tool spindle is stably supported and can rotate smoothly without frictional resistance, so it can move accurately according to the center of gravity and can stand still smoothly, making it easy to find the center of gravity of an unbalanced tool. Therefore, the balance work does not take much time and balance can be performed with very high precision.Furthermore, the tool can be attached to the device very easily with one touch.

Therefore, the present invention provides a static pressure bearing in the cylindrical portion of the main body of the device so that the tool support shaft is statically supported by pressurized air, and a locking member that contacts the center of the tool support shaft from the rear. It was established.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Configuration of the Invention The tool balancing device of the present invention will be described below with reference to the drawings, giving specific examples.

Figure 1 is a side view of the tool balancing device 1 of the present invention, Figure 2 is a side view of the tool balancing device 1 of the present invention;
The figure is a plan view thereof, and FIG. 3 is a sectional view of the cylindrical portion 2.3.

The tool balancing device 1 communicates with the first cylindrical portion 2, which has a horizontal first cylindrical portion 2, a second cylindrical portion 3 connected thereto, and leg portions 4 that support these cylindrical portions 2.3. A device main body 6 having an air supply hole 5, a radial metal 7 as a radial static pressure bearing fitted to the inner periphery of the first cylindrical portion 2 of this main body 6, and a radial metal 7 that is connected to the radial metal 7 through a static pressure bearing space 24. It is rotatably fitted loosely and has a tool (here, a grindstone) at the front end.
8 is removably held, and the second cylindrical portion 3 is attached at the rear end.
a tool support shaft 10 having a flange portion 9 located therein;
A flange portion 9 is provided on the bearing center axis ilL of the device main body 6, facing the rear end surface of the flange portion 9 of the tool support shaft 10.
It is constituted by a locking member 11 that contacts from the center and from the rear.

The main body 6 of the apparatus is integrally formed with a hollow first cylindrical portion 2 having both horizontal end faces open at the upper portion thereof, and leg portions 4 for fixing and supporting the cylindrical portion 2 horizontally at the lower portion thereof. Three legs 12, 13, and 14 are provided on the bottom of the leg 4, with two #1 legs at the front.
2.13 is fixed at a symmetrical position with respect to the central axis of the cylindrical part 2.3, and the rear #14 is adjusted up and down with a screw at a position along the central axis of the cylindrical part 2.3. It can be installed freely. That is, this #14 serves as a horizontal adjustment member of the device 1. Further, an air supply hole 4 is formed in one section of the leg portion 4, and exhaust holes 15, 16 are formed in one side portion of the cylindrical portion 2.3 so as to communicate with the inside.

Two radial metals 7 are provided at the front and rear of the first cylindrical portion 2 in the axial direction. Each radial metal 7.7 is hermetically fitted and fixed to the inner periphery of the first cylindrical portion 2 via an O-ring 17, and a collar 18 is interposed between both metals 7.7. .

Each radial metal 7.7 has an air pocket 19 formed on its inner circumferential surface, and each air pocket 19 communicates with the air supply hole 4 inside the main body 6 through a respective supply path 20.

The tool support shaft 10 removably holds the center of a tool, that is, the grindstone 8 here, and has a conical tool holding portion that fits into a tapered mounting hole 21 formed at the center of the grindstone 8 at its front end. 22 and a small diameter shaft portion 23 for preventing tool removal is integrally formed at its tip. Further, a flange portion 9 having a diameter larger than the inner diameter of the first cylindrical portion 2 is integrally formed at the rear end portion of the tool support shaft 10, and is located rearward from the rear end surface of the first cylindrical portion 2. A hydrostatic bearing space 24 is formed between the intermediate portion of the tool support shaft 10 and the inner circumferential surfaces of the front and rear radial metals 7.7, whereby the tool support shaft 10 is rotatably supported in a floating manner.

In addition, a second tube is provided on the same axis at the rear of the first cylindrical portion 2.
The cylindrical portion 3 is fixed with screws or the like.

The second cylindrical portion 3 has a larger inner diameter than the first cylindrical portion 2, is provided so as to cover the flange portion 9 with space between the outer periphery and the front and rear surfaces, and has a plurality of tubes on the periphery and the rear. An exhaust hole 16.25 is formed to allow air inside the cylinder portion 2.3 to escape to the outside. In addition, a locking member 11 is provided in the guide hole 26 of the center shaft of the second cylindrical portion 3 for lightly contacting the center of the rear end surface of the flange portion 9, that is, the center of the tool support shaft 10 from the rear, and positioning it in the axial direction. is compression spring 2
The forward protruding position of the locking member 11 is regulated by an external adjustment nut 28 screwed onto the rear end.

The protruding tip of the locking member 11 is formed in a spherical shape to minimize the area of contact with the center of the rear end surface of the flange portion 9 and to minimize frictional resistance.

Furthermore, a front cover 30 passing through the tool support shaft 10 is fixed to the front part of the first cylindrical part 2 with screws or the like. Furthermore, a ring-shaped blue line 31 and a red line 32 are respectively carved on the outer peripheral portion of the front end of the tool support shaft 10 as marks for confirming the axial position.

A blue line 31 indicates a space 29 between the front end surface of the flange portion 9 and the rear end of the first cylindrical portion 2 when the flange portion 9 contacts the locking member 11 when the tool support shaft 10 is in the horizontal storage position as shown in FIG. The front cover 30 is provided at a position where it can be visually seen from the front edge of the front cover 30 when the front cover 30 is in the correct position in the axial direction.

The red line 32 indicates the position of the front cover 30 when the tool support shaft 10 moves forward from the state shown in FIG. It is provided at a position exposed from the front edge. That is, this red line 31 is a red signal that indicates an incorrect position of the tool spindle 10 in the axial direction.

Effect of the embodiment Next, the operation of the device of the present invention will be explained.

FIG. 3 shows a state in which the tool support shaft 10 is statically supported by pressurized air by the present device 1, and the grindstone 8 is attached to the tool holding portion 22 of the support shaft 10.

The pressurized air is supplied from the air supply hole 5 of the main body 6 by an air supply device 33 installed in the factory, for example, and
116, from each air pocket 19 to the hydrostatic bearing space 2
It is sprayed towards 4.

As a result, the support shaft 10 receives static pressure in the radial direction,
It is statically supported in a non-contact manner by the static pressure bearing space 24 inside the radial metal 7.7. At the same time, a portion of the pressurized air that has flowed into each radial metal 7
．． The gas is ejected in the axial direction from the gaps at both ends of the holes 7, and is discharged to the outside through the gaps in the front cover 30 and the exhaust holes 15, 16, and 25.

The air blown toward the second cylindrical portion 3 acts to urge the flange portion 9 rearward and bring it into light contact with the protruding tip of the locking member 11. As long as the device 1 is kept horizontal, the support shaft 10 is always stably held at this correct position.

Therefore, there is almost no frictional resistance due to contact between the support shaft 10 and the cylindrical portion 2.3, and the support shaft 10 is stably supported in a completely floating state and can freely rotate.

Next, a procedure for actually balancing the grindstone 8 using the tool balancing device 1 will be described with reference to FIG. 4.

First, the device 1 is horizontally adjusted. You may also use a spirit level, or use the blue line 31 of the support shaft 10 as a reference to confirm the correct position of the support shaft 10.
4. Perform horizontal adjustment in the axial direction while adjusting the rotation. In addition,
Horizontal adjustment in the left and right directions is not required.

Next, in order to attach the grindstone 8 to the spindle 10, the attachment hole 21 of the grindstone 8 is inserted into the tool holder 22.

The attachment hole 21 and the tool holding portion 22 fit into each other with their tapered surfaces, and centering is performed. At this time, the grindstone 8 is connected to the device 1.
Even if the support shaft 10 is pushed against the locking member 11 and the rear end surface of the flange portion 9 is inserted into the second
Since the grindstone 8 is stopped when it hits the cylindrical portion 3, the grindstone 8 is more firmly attached to the spindle 10. When the hand is released, the locking member 11 pushes the support shaft 10 forward by the elastic force of the spring 27, and the support shaft 10 floats in a well-balanced manner to the correct position as shown in Fig. 3 with the help of internal air pressure. Supported.

In other words, installation can be completed with one touch.

Next, find the direction of the center of gravity. When you let go of the whetstone 8, if the whetstone 8 is not balanced at all, the whetstone 8 and the spindle 10 slowly rotate within the cylindrical portion 2.3 until the center of gravity of the whetstone 8 is directly below. Stop at .

Attach the balance piece here. This method is carried out using a procedure similar to the conventional method using, for example, three pieces.

That is, in this state, the center of gravity is directly below, so as shown in FIG. Attach pieces. In this state, let go of the grindstone 8 and compare the balance between the center of gravity side of the grindstone 8 and the balance 035 side. If the center of gravity is still heavy, move it to the side of the balance piece 35 attached earlier, and conversely, if the balance piece 35 is heavier, move it further to the center of gravity side as shown in Fig. 4 [11].
Balance pieces 36 and 37f: Attach them approximately symmetrically.

Now, with these two balance pieces 36 and 37 attached, if you lightly release your hand from the grindstone 8 again and repeat this operation several times and it always stands still at the same angle, the position directly below it will be heavy. For example, as shown in Fig. 4 [III], if the two balance pieces 36 and 37 installed later are located on the lower side, these two balance pieces 36 and 37 are attached to the previous one. It is sufficient to bring the balance piece 35 closer to the balance piece 35 side by the same amount on both sides, and if the two balance pieces 36 and 37 are on the upper side as shown in Figure 4 [II], the first balance piece 85 side is heavier. and the remaining two balance pieces 36
．． 37 is moved in the direction away from one balance piece 35 by the same amount.

If such an operation is repeated and the rest angle of the grindstone 8 is no longer constant, it means that the grindstone 8 is balanced in all directions. And during the grinding work, the balance piece 35.36.8
Tighten all pieces 35, 36, and 37 so that 7 does not move.

With the above, balancing of the grindstone 8 is completed. Then, this grindstone 8 is pulled out from the spindle 10 and removed from the device 1. At this time, simply by pulling the grindstone 8 from the device 1, the flange portion 9 of the support shaft 10 hits the rear end surface of the first cylindrical portion 2 and is stopped, and the grindstone 8 is easily removed.

If the red line 32 appears during the balancing work, it means that the flange part 9 is in contact with the cylinder part 2, so stop the work once and move the support shaft 10 backward until the blue line 31 appears. move it.

At the same time, the horizontal accommodation of the device 1 is also confirmed. If the support shaft 10 is held in the correct position, the work continues.

Here, we have explained a method for performing balance adjustment using three balance pieces 85, 36, and 37, but the balance adjustment is not limited to this method; it is also possible to easily adjust balance using two balance pieces as is conventionally done. It can be performed.

In addition, in the above embodiment, the example of the grindstone 8t' was explained as a tool, but not only such a grindstone 8 but also the tool spindle 1
The same applies to other tools that can be attached to 0.

Furthermore, since the tool spindle 10 can be easily pulled out from the rear from the main body 6 and can be attached to the main body 5, for example, the tool spindle 10' having an adapter mounting hole 38 at the front end as shown in FIG. It can also be installed. And, for example, the fifth
It is also possible to attach an adapter 39 as shown in the figure to the attachment hole 38 and attach various tools to the support shaft 10' via this adapter 89. In other words, it is possible to balance various types of tools with the same effect as in the above embodiment, resulting in extremely high versatility.

Further, instead of the compression spring 27 for resiliently supporting the locking member 11, various resilient means such as an air cushion may be used.

Further, in this embodiment, the first cylindrical part 2 and the second cylindrical part 3 are made of separate members, but the same effect can be achieved even if they are made of the same member and the locking member 11 is held by a plate-like member from the rear. play.

As described in detail, the present invention provides a radial static pressure bearing in the main body of the device, which consists of a horizontal first cylinder part, a second cylinder part connected thereto, and legs supporting these parts, and , a tool support shaft that holds a tool at the front end and has a flange portion located in the second cylinder portion at the rear end is rotatably supported, and a locking member and the flange portion are provided on the central axis of the bearing. Since a space is formed between the second cylindrical part and the flange by biasing it in the direction in which the rear end surface comes into contact with it, the tool support shaft is not in contact with the bearing and is stably held in the axial direction. Since it can rotate freely in a fixed position, it can rotate and stand still smoothly.
Accurate movement according to the position of the center of gravity of the tool can be obtained, so the center of gravity position where the tool is unbalanced can be easily found, and balancing work can be performed accurately in a short time.

In addition, since there is no friction between the inner peripheral surface of the bearing and the surface of the spindle,
There is no need to maintain accuracy on both surfaces, and there is no wear or heat generation, making the device extremely durable.

Furthermore, even if the bearing is used in a factory where there is a lot of dirt and dust in the air, since the air is blown out from inside the bearing, there is no fear that dust will accumulate inside the bearing, and maintenance is easy.

In addition, the horizontal adjustment of the device during use only requires adjusting the levelness in the axial direction.Therefore, it is sufficient to install a horizontal adjustment member on one side along the central axis, which makes adjustment easy and allows easy installation of the device. It can be installed anywhere without the need to select a location.

Furthermore, when the tool is attached or detached, the tool spindle moves in the front-rear direction and the second
Since it can be butted back and forth within the cylinder, no force is required to attach or remove tools, and it can be easily attached and removed with one touch. In addition, the locking member makes light contact with the shaft center and is always positioned at the correct position in the axial direction. Therefore, the assembly of the tool support shaft in the thrust direction to the cylindrical portion does not require any precision.

Further, the air can be used at a pressure similar to that of an air supply device installed in a general factory, and no special equipment is required.

Balancing work can be done in a short amount of time without the need for the extremely complicated and detailed work required in the past, as the tool is supported statically by simply attaching it to the spindle and its movement can be easily observed in a fixed position. Accurate balance can be achieved. This results in
The tool balance accuracy has become extremely high.

In addition, a mark is provided on the outer periphery of the front end of the tool spindle to confirm the axial position, so if the tool spindle moves forward for some reason, it can be easily detected and quickly returned to the correct position. Since it can be returned to its original position, contact with the cylindrical portion can be prevented and accurate balancing can be continued.

[Brief explanation of drawings]

Fig. 1 is a side view showing the device of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a horizontal sectional view of the cylindrical part, Fig. 4 [1] [II
] [II] is an explanatory diagram showing a balancing method, FIG. 5 is a simplified horizontal sectional view of a cylindrical portion showing a modification of the present invention, and FIG. 6 is a perspective view showing a conventional device. DESCRIPTION OF SYMBOLS 1... Balancing device, 2... First cylinder part, 3...
・Second cylinder part, 4... Leg part, 5... Air supply hole, 6...
Device body, 7... Radial metal as radial static pressure bearing, 8... Grindstone as tool, 9... Flange portion, 10.10'... Tool support shaft, 11... Locking member ,
29... Space, 31. 32... Blue line as a marker, red line, L... Central axis line.

Claims (2)

[Claims] (1) A device main body consisting of a horizontal first cylinder part, a second cylinder part connected thereto, and legs supporting these cylinder parts, and having an air supply hole communicating with at least the first cylinder part; A radial static pressure bearing fitted on the inner periphery of the first cylindrical part; a radial static pressure bearing that is rotatably loosely fitted in the radial static pressure bearing, has a front end that removably holds a tool, and a rear end that is located within the second cylindrical part. A tool support shaft formed with a flange portion, and a locking member provided on the radial hydrostatic bearing center axis of the device main body opposite to the rear end surface of the flange portion of the tool support shaft,
By supplying air into the first cylindrical part from the air supply hole, the tool support shaft is statically supported, and the tool support shaft is biased in the direction in which the locking member and the flange part come into contact with each other, and the second cylinder A tool balancing device characterized by forming a space between the flange portion and the flange portion. (2) Claim 1, characterized in that markings for confirming the axial position are provided on the outer periphery of the front end of the tool support shaft.
Tool balancing device as described in section.