JP2003117813A - Work rest device and method of controlling the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work rest device enabling highly accurate grinding by movably following up the supporting position of shoes on the outer peripheral surface of the machined portions of a work according to variations in outside diameter dimensions of the machined portions, and a method of controlling the device. SOLUTION: This work rest device comprises the shoes 30a and 31a for supporting the machined portions Wa to We of the work W when the outer peripheral surface of the work W is ground while rotating the long work W about the axis L thereof in the state of supporting the work at both ends. The support positions P1 and P2 of the shoes 30a and 31a on the machined portions Wa to We of the work W are controllably changed in the radial direction of the machined portions Wa to We by a control device 41 based on the variation amounts o1 and o2 of the outer peripheral surfaces of the machined portions Wa to We according to a rotating angle between the machined point P0 of the work W and the support positions P1 and P2 of the shoes 30a and 31a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work rest device for supporting a processed portion of a work and a control method thereof when grinding an outer peripheral surface of a long work such as an engine crankshaft. is there.

[0002]

2. Description of the Related Art Generally, when grinding the outer peripheral surface of a long work such as a crankshaft with a grinding machine,
While the work is supported between a pair of headstocks at both ends, the grinding wheel is brought into contact with a predetermined processing portion of the work while rotating around the axis, and the outer peripheral surface of the processing portion is ground. During this grinding process, the workpiece may bend due to the grinding resistance of the grinding wheel, etc., causing a deviation between the center of rotation of the headstock and the shaft center of the machined part of the workpiece, which may lead to a reduction in grinding accuracy. is there. In order to prevent such problems, in the case of a grinding machine that grinds the crankshaft, etc., the shoe is brought into contact with the outer peripheral surface of the work part of the work piece from the opposite side of the grinding wheel to work the work piece. It is equipped with a work rest device designed to support the part.

[0003]

However, in this conventional work rest device, during cutting of the work,
Regardless of the grinding speed of the outer peripheral surface of the processed portion, the shoe is pressed against the outer peripheral surface of the processed portion toward the center of the work with a constant pressure toward the center of the work by a cylinder or the like. In this case, since the outer peripheral surface of the work is continuously cut, the radius dimension of the processed portion continues to change as the grinding progresses. Moreover, the shoe presses toward the center of rotation of the work, but as described above, the outer peripheral surface of the work continues to change, so the center of rotation of the work and the center of the outer dimension of the machined part Do not match. For this reason, the work may move eccentrically, and the shoe cannot follow it. Therefore, there is a problem that the supporting position of the shoe with respect to the outer peripheral surface of the processed portion of the work does not immediately correspond to the grinding state of the outer peripheral surface of the processed portion, and high-precision grinding processing cannot be performed.

The present invention has been made by paying attention to the problems existing in such conventional techniques. The purpose of the work rest device is to enable the shoe supporting position with respect to the outer peripheral surface of the machined part of the workpiece to be moved in accordance with the grinding state of the outer peripheral surface of the machined part, thereby performing highly accurate grinding. And a method of controlling the same.

[0005]

In order to achieve the above object, the invention according to claim 1 is such that while a long work is supported by its both ends while rotating about its axis,
When grinding the outer peripheral surface of a work, in a work rest device that supports a cylindrical portion that is being ground, a shoe that is provided on a processed portion whose dimension in the radial direction of the work changes according to the rotation angle of the work. A control means is provided for controlling the movement of the support position of the machined part so as to follow the machined part, and the control means is the amount of displacement of the outer peripheral surface of the machined part according to the rotation angle from the machining point of the workpiece to the shoe support position. It is characterized in that the support position of the shoe is controlled to be moved according to.

Therefore, according to the first aspect of the present invention, during grinding of the machined portion of the workpiece, the supporting position of the shoe with respect to the outer peripheral surface of the machined portion is determined by the grinding state of the outer peripheral surface of the machined portion, that is, The setting can be changed at any time according to the amount of displacement. Therefore, the supporting position of the shoe with respect to the outer peripheral surface of the processed portion of the work can be immediately adapted to the cylindrical radius of the outer peripheral surface of the processed portion, and the work can be ground with high accuracy.

According to a second aspect of the present invention, in the first aspect of the present invention, the control means sets a radius dimension of a processing point during grinding, and a rotational angle difference from the processing point to a shoe support position. When R and the cutting speed of the processing point are q, the distance D from the rotation center of the work to the support position of the shoe is calculated based on the following equation (1).

D = d + (R / 2π) × q (1) where q is the cut amount per one revolution of the work (mm / re
v), which is called the cutting speed.

Therefore, according to the second aspect of the invention, the supporting position of the shoe from the rotation center of the work can be easily calculated based on the equation (1). According to a third aspect of the present invention, in the first or second aspect of the present invention, storage means is provided for storing the displacement amount of the outer peripheral surface of the processed portion according to the rotation angle, and the control means is the storage means. The supporting position of the shoe is changed and controlled based on the displacement amount stored in advance.

Therefore, according to the third aspect of the present invention, unlike the case where the displacement amount is calculated by the calculation based on the displacement amount stored in the storage means, the calculation time for the displacement becomes unnecessary. It is possible to easily change and control the support position of the shoe in response to the displacement of the outer peripheral surface of the work.

According to a fourth aspect of the present invention, when the outer peripheral surface of the work is ground while the long work is supported by its both ends and is rotated about its axis, the work portion of the work is In a method of controlling a work rest device having a supporting shoe, the supporting position of the shoe with respect to the processed portion of the work is controlled to be changed in the radial direction of the processed portion according to the rotation angle of the work. .

Therefore, according to the invention described in claim 4, it is possible to obtain the same operation as the operation described in claim 1. According to a fifth aspect of the invention, in the invention according to the fourth aspect, based on the displacement amount of the outer peripheral surface of the processed portion according to the rotation angle difference from the processing point of the work to the support position of the shoe, It is characterized in that the support position is changed and controlled.

Therefore, according to the invention described in claim 4, it is possible to obtain an operation substantially similar to the operation described in claim 1.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, in this grinding machine, a work support device 12 is arranged on a base 11. That is, the moving table 13 is supported on the upper surface of the base 11 so as to be movable in the X direction via the pair of guide rails 14. A pair of headstocks 15 and 16 are supported on the upper surface of the moving table 13 so as to be movable in the X direction via guide rails 17, and opposite ends thereof support a work W such as a crankshaft at both ends. Chucks 15a, 16a are provided.

A grindstone device 18 is provided on the base 11 so as to correspond to the work supporting device 12. That is, a grindstone base 19 is supported on the upper surface of the base 11 so as to be movable in the Y direction via a pair of guide rails 20, and a processing head 21 is arranged on the upper surface thereof. A rotating shaft 22 is rotatably supported by the processing head 21, and a grinding wheel 23 is attached to the tip thereof.

A motor 2 for rotating a grindstone is mounted on the grindstone base 19.
4 is provided, and by this motor 24, pulleys 25, 2
The grinding wheel 23 is rotated via 6 and the belt 27. A motor 2 for moving a grindstone is provided at the rear end of the base 11.
8 is provided, and the grindstone 19 is moved by the motor 28 in the Y direction via a ball screw (not shown).

When the processing portions Wa to We such as journals of the work W such as the crankshaft are ground, the work W is paired with a pair of headstocks 15, 1.
The table 13 is mounted between 6 and the moving table 13 is moved in the X direction by a table moving motor (not shown). By this movement, the predetermined processed portions Wa to We of the work W are arranged corresponding to the grinding wheel 23. In this state, the work W is rotated about the axis L by a work rotation motor (not shown). At the same time, the grinding wheel 23 is moved toward the workpiece W in the Y direction at a predetermined cutting speed by the grinding wheel moving motor 28 while being rotated by the grinding wheel rotating motor 24 at a predetermined rotation speed. By this approach movement,
The grinding wheel 23 is brought into contact with predetermined processing parts Wa to We of the work W, and the outer peripheral surfaces of the processing parts Wa to We are ground.

As shown in FIGS. 1 and 2, the base 11 is
A work rest device 29 is disposed on the upper side, and when the predetermined processed portions Wa to We of the work W are ground, the work rest devices 29 cause the processed portions Wa to We to face the grinding wheel 23. It is supposed to be supported. That is, the first support arm 30 and the second support arm 31 are rotatably supported on the base 11 via the support shaft 32, and the tip ends of the first support arm 30 and the second support arm 31 are provided on the outer peripheral surfaces of the processed portions Wa to We of the workpiece W. A first shoe 30a and a second shoe 31a that come into contact with each other from the side and the bottom are provided.

A spring 33 is mounted on the first support arm 30, and the spring 33 causes the first support arm 30 to move in the counterclockwise direction in FIG. It is urged to rotate away from We. A spring 34 is mounted on the second support arm 31, and the spring 34 causes the second support arm 31 to move in the clockwise direction of FIG. 2, that is, in the direction in which the second shoe 31a is separated from the processed portions Wa to We of the work W. It is biased to rotate.

A plunger 35 is brought into contact with the end portion of the first support arm 30, and a first servomotor 36 as a driving means is operatively connected to the plunger 35 via a ball screw (not shown). The rotation of the first servo motor 36 causes the ball screw and the plunger 3 to rotate.
The first support arm 30 is rotated via 5 to move and arrange the first shoe 30a at a predetermined support position with respect to the outer peripheral surfaces of the processed portions Wa to We of the work W.

A plunger 37 is connected to an end of the second support arm 31, and a second servomotor 38 as a driving means is operatively connected to the plunger 37 via a ball screw (not shown). The rotation of the second servomotor 38 causes the ball screw and the plunger 3 to rotate.
The second support arm 31 is rotated via 7 to move and arrange the second shoe 31a at a predetermined support position with respect to the outer peripheral surfaces of the processed portions Wa to We of the work W.

Next, the circuit configuration of the work rest device 29 configured as described above will be described. As shown in FIG. 3, a control device 41 as a control device is connected to a memory 42 as a storage device, an input device 43 such as a keyboard, and the servomotors 36 and 38. Then, as shown in FIG. 4, the memory 42 receives an input from the input device 43, and as shown in FIG. 4, the support positions P of the shoes 30a and 31a from the processing point P0 with respect to the processing portions Wa to We of the work W.
Processed parts Wa to We according to the rotation angle difference between 1 and P2
The displacement amounts o1 and o2 of the outer peripheral surface of are stored in advance.

That is, as shown in FIGS. 4 and 5, during grinding of the processed portions Wa to We of the work W, the outer peripheral surface of the processed portions Wa to We is cut from the processing point P0 to each shoe 30.
By being rotated to the support positions P1 and P2 of a and 31a, displacement of the cutting amount according to the rotation angle difference occurs. In this case, from the processing point P0 to each shoe 30a, 31a
The rotation angle difference between the support positions P1 and P2 of R1 and R2
(Degrees), when the cutting speed of the processing point P0 is q (mm / rev), the support positions P1 and P of the shoes 30a and 31a are set.
The displacement amounts o1 and o2 (mm) in 2 are represented by the following equations (2) and (3), and the displacement amounts o1 and o2 are stored in the memory 42 together with the movement control position data of the wheel head 19.

O1 = (R1 / 2π) × q (2) o2 = (R2 / 2π) × q (3) Further, the control device 41 controls the machining portion Wa of the work W to
The displacement amount o stored in the memory 42 during the grinding process of We
The support positions P1 and P2 of the shoes 30a and 31a are changed and controlled based on 1 and o2. That is, as shown in FIG. 4, when the radius dimension of the processing point P0 during grinding is d,
Each shoe 3 from the rotation center La on the rotation axis L of the work W
Distances D1 and D to support positions P1 and P2 of 0a and 31a
2 (mm) is calculated based on the following equations (4) and (5).

D1 = d + o1 = d + (R1 / 2π) × q (4) D2 = d + o2 = d + (R2 / 2π) × q (5) Then, the control device 41 controls the position of the wheel head 19 by movement control. Based on the data and the calculated values of the distances D1 and D2, the first servomotor 36 and the second servomotor 38
To support the shoes 30a, 31a at the support positions P1,
Change control of P2. Therefore, the processed portion W of the workpiece W
Each shoe 3 according to the displacement accompanying the grinding process of a to We
0a and 31a can change the support positions for the processed portions Wa to We.

Therefore, according to this embodiment, the following effects can be obtained. (A) In the work rest device 29, when the outer peripheral surface of the work W is ground, the processed portion Wa of the work W to
A pair of shoes 30a and 31a that support We are provided. Then, by the control device 41, the processed portion Wa-
The support positions P1 and P2 of the shoes 30a and 31a with respect to the outer peripheral surface of the We are determined from the machining point P0 of the work W to the shoes 3 respectively.
0a, 31a displacement amounts o1, o2 of the outer peripheral surfaces of the processed portions Wa to We according to the rotation angle difference between the support positions P1, P2.
Based on the above, the machining portions Wa to We are controlled to be changed in the radial direction.

Therefore, the processed portions Wa to We of the work W are
During the grinding process, the support positions P1 and P2 of the shoes 30a and 31a with respect to the outer peripheral surfaces of the processed parts Wa to We are
The setting can be changed at any time according to the grinding state of the outer peripheral surfaces of the processed portions Wa to We. Therefore, the work W can be ground with high precision.

(B) In this work rest device 29, the radius dimension of the processing point P0 during grinding is d, and the processing point P0 is
To the support positions P1 and P2 of the respective shoes 30a and 31a are R1 and R2, and the cutting speed of the machining point P0 is q.
Then, the distances D1 and D2 from the rotation center La on the rotation axis L of the work W to the support positions P1 and P2 of the shoes 30a and 31a are calculated based on the following equations (4) and (5). It is like this.

D1 = d + (R1 / 2π) × q (4) D2 = d + (R2 / 2π) × q (5) Therefore, each shoe 30 from the rotation center La of the work W is determined.
The support positions P1 and P2 of a and 31a can be easily calculated based on the equations (4) and (5).

(C) In the work rest device 29, the displacement amounts o1 and o of the outer peripheral surfaces of the processed parts Wa to We corresponding to the rotation angle differences of the shoes 30a and 31a.
A memory 42 for storing 2 is provided. Then, the displacement amount o previously stored in the memory 42 together with the position data by the movement control of the grindstone 19 by the controller 41
The support positions P1 and P2 of the shoes 30a and 31a are controlled to be changed based on 1 and o2. Therefore, the support positions P1 and P2 of the shoes 30a and 31a can be easily changed and controlled based on the displacement amounts o1 and o2 stored in the memory 42.

(D) In the work rest device 29, the support positions P1 and P of the shoes 30a and 31a are provided.
Servo motors 36 and 38 are used as driving means for changing the number 2. Therefore, by driving the servo motors 36 and 38, the support positions P1 of the shoes 30a and 31a are
P2 can be accurately changed and controlled.

(Modification) This embodiment can be modified and embodied as follows. In the above-described embodiment, the crankshaft is used as the work, but other than this, for example, the camshaft is used as the work.

In the above embodiment, the processed portion is the journal of the crankshaft, but the processed portion is the crankpin. In the above embodiment, the processed portion Wa of the work W
To We, the first support arm 30 and the second support arm 31 are rotatably arranged, and the support arms 3
The first shoe 30a and the second shoe 31 are attached to the end portions of 0 and 31.
a was provided. On the other hand, the first shoe 30a and the second shoe 31a are attached to the processed portion W of the work W.
It is arranged so as to be linearly movable in the radial direction with respect to the outer peripheral surfaces of a to We, and is configured to be moved by a first servomotor 36 and a second servomotor 38 via a ball screw. With this configuration, the shoe 30
Since a and 31a can be displaced in the radial direction with the center of the work W as the center, no force in the eccentric direction acts on the work W, and the machining accuracy can be further improved.

In the above embodiment, the outer peripheral surface of the processed portions Wa to We of the work W has two shoes 30a, 3a.
Although it is supported by 1a, it should be configured so as to support the work so as to be held by two or more shoes. Even in the case of such a configuration, the effect can be obtained by means substantially similar to those of the above-described embodiment.

[0035]

As described above in the embodiment, in the present invention, the supporting position of the shoe with respect to the outer peripheral surface of the machined part of the work can be changed according to the grinding state of the outer peripheral surface of the machined part. It is possible to achieve the effect that high precision grinding can be performed.

[Brief description of drawings]

FIG. 1 is a plan view showing a grinder equipped with a work rest device according to an embodiment.

FIG. 2 is an enlarged side view showing the work rest device of FIG.

FIG. 3 is a block diagram showing a circuit configuration of a work rest device.

FIG. 4 is an explanatory view for explaining the operation of the work rest device.

FIG. 5 is a graph showing the relationship between the rotation angle of the work and the depth of cut.

[Explanation of symbols]

11 ... Base, 12 ... Work support device, 13 ... Moving table, 15, 16 ... Spindle base, 18 ... Grinding wheel device, 19 ... Grinding wheel stand, 21 ... Machining head, 23 ... Grinding wheel, 29 ... Work rest device, 30 ... 1st support arm, 30a ... 1st shoe, 31 ... 2nd support arm, 31a ... 2nd shoe, 36
... first servo motor as drive means, 38 ... second servo motor as drive means, 41 ... control device as control means, 42 ... memory as storage means, W ... work,
Wa ... Machining part, L ... Rotation axis, P0 ... Machining point, P1,
P2 ... Support position, D1, D2 ... Rotation angle difference, o1, o2
… Amount of displacement.

Claims (5)

[Claims] 1. A work rest device for supporting a cylindrical portion during grinding when grinding an outer peripheral surface of a work while rotating a long work while supporting it at both ends while rotating it about its axis. In the above, in accordance with the rotation angle of the work, a control means is provided for controlling the movement of the supporting position of the shoe provided on the processing part whose dimension in the radial direction of the work changes so as to follow the processing part. The means is characterized in that the support position of the shoe is controlled to move according to the amount of displacement of the outer peripheral surface of the processed portion according to the rotation angle from the processing point of the work to the support position of the shoe. Rest device. 2. The rotation of the workpiece when the radius dimension of the machining point during grinding is d, the rotation angle from the machining point to the support position of the shoe is R, and the cutting speed of the machining point is q. The distance D from the center to the shoe support position can be calculated by the following equation (1).
The work rest device according to claim 1, wherein the work rest device is calculated based on D = d + (R / 2π) × q (1) 3. A storage means for storing the displacement amount of the outer peripheral surface of the machined portion according to the rotation angle is provided, and the control means controls the change of the support position of the shoe based on the displacement amount previously stored in the storage means. The work rest device according to claim 1 or 2, wherein 4. Control of a work rest device for supporting a processed portion of a workpiece when grinding an outer peripheral surface of the workpiece while rotating the long workpiece while supporting it at both ends while rotating it about its axis. The method of controlling a work rest device according to the above method, further comprising controlling movement of a support position of the shoe with respect to a processed portion of the work so as to follow the processed portion according to a rotation angle of the work. 5. The support position of the shoe is controlled to be changed based on the displacement amount of the outer peripheral surface of the processed portion according to the rotation angle difference from the processing point of the work to the support position of the shoe. 4. The method for controlling the work rest device according to item 4.