JP2000033529A - Main shaft device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a main shaft device facilitating maintenance and inspection, allowing the use of a compact brake device and a general-purpose encoder, and facilitating the exchange of parts without prolonging a main shaft. SOLUTION: An auxiliary shaft 84 is rotatably supported in parallel with a main shaft 20, and the rotation of the main shaft 20 is transmitted to the auxiliary shaft 84 through a transmission gear 82 and a gear 86. An electromagnetic brake 92 and an encoder 94 are attached to an end part of the auxiliary shaft 84. Since a braking force acts on the main shaft 20 by operating the electromagnetic brake 92 it is unnecessary to provide a brake means having a large diameter in an intermediate part of the main shaft 20. Moreover, since the encoder 94 is not attached to the intermediate part of the main shaft 20 but is attached to the end part of the auxiliary shaft 84, it is unnecessary to use an encoder having a special shape. Furthermore, it is possible to shorten a total length of the main shaft 20 and facilitate maintenance and inspection works because it is attached to the end part of the auxiliary shaft 84.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device provided in a grinding device for transmitting a rotational force to a workpiece.

[0002]

2. Description of the Related Art As shown in FIG. 5, journals J at both ends of a crankshaft W are held by a hydraulic chuck 102 in a crankpin grinding apparatus 100.
02 with the built-in motor 1
A spindle device 108 for rotating at 06 is provided. A phase indexing device 112 is attached to an end of the indexing shaft 110 that penetrates through the main shaft 104 and contacts the crankshaft W,
The phase of the crank pin P is determined by the phase determining device 112.

When the crankshaft W is large, main spindle devices 108 are arranged on both sides of the crankshaft W, and the journals J at both ends of the crankshaft W are provided.
Need to be held by the chucks 102 and driven to rotate synchronously, and an encoder (not shown) for detecting the rotational angle position of the main shaft 104 needs to be provided.

Further, since the chuck 102 is eccentric, in order to stop the main shaft 104 at an arbitrary angular position,
Alternatively, if the control device for controlling the rotation of the built-in motor 106 breaks down for some reason and becomes uncontrollable, if the rotation synchronization of the left and right main shafts 104 is shifted, the crankshaft W is twisted, and in the worst case the crankshaft W Since the shaft W is damaged, a brake device is also required to mechanically stop the rotation of the main shaft 104.

However, since the phase indexing device 112 is attached to the rear end of the main shaft 104, an encoder or a brake device cannot be mounted to the rear end of the main shaft 104.

On the other hand, if a brake device is provided at an intermediate portion of the main shaft 104, it is necessary to increase the size of the brake device in order to obtain a necessary braking force. Further, the total length of the main shaft 104 is increased by the amount of the brake device.

Further, in order to mount the encoder at the intermediate portion of the main shaft 104, a hollow special-shaped encoder must be used. In the middle part of the main shaft 104,
When it is difficult to perform maintenance or inspection work on the encoder or the brake device, and when it is necessary to replace parts, the spindle device 108
Must be disassembled.

[0008]

SUMMARY OF THE INVENTION In consideration of the above facts, the present invention facilitates maintenance and inspection without lengthening the spindle.
Another object of the present invention is to provide a spindle device that can use a small-sized brake device or a general-purpose encoder and that can easily replace components.

[0009]

According to the first aspect of the present invention, a gripping means is provided at an end of a main shaft rotatably supported. The workpiece is gripped by the gripping means, and a rotational force of a main shaft directly rotated by a motor is applied to the workpiece.

An auxiliary shaft is rotatably supported in parallel with the main shaft, and the rotation of the main shaft is transmitted to the auxiliary shaft by a transmission means. A brake means is provided at one end of the auxiliary shaft, and by operating the brake means, a braking force is applied in the order of the auxiliary shaft, the transmission means, and the main shaft.

In this configuration, a functional member (for example, an encoder or a phase indexing device) other than the brake means can be attached to the other end of the main shaft. Further, since there is no need to provide a brake means in the middle part of the main shaft, a brake means having an appropriate capacity is sufficient without using a large-diameter brake means. Further, the total length of the main shaft can be shortened, and the maintenance and inspection work of the brake means becomes easy.

According to the second aspect of the present invention, the encoder is provided at the other end of the auxiliary shaft. As described above, since it is attached to the other end of the auxiliary shaft instead of the intermediate portion of the main shaft, a general-purpose encoder can be used, and maintenance and inspection work is facilitated.

According to the third aspect of the present invention, the transmitting means includes:
It is arranged near the holding means of the main shaft. in this way,
By providing the position near the gripping means via the auxiliary shaft, the detection error of the rotation angle due to the twist of the main shaft can be reduced.

[0014] In the invention described in claim 4, the transmitting means is:
The gear mechanism is configured to increase the rotation speed of the main shaft and transmit the speed to the auxiliary shaft. Since the gear does not undergo elongation or thermal deformation as compared with a belt or the like, the rotational force of the main shaft can be transmitted to the auxiliary shaft with high accuracy.

Further, by increasing the number of revolutions of the main shaft by setting the number of gear teeth, the rotation angle of the main shaft can be detected with high accuracy without using a high-resolution encoder. The braking force also increases. The backlash of the gear may be removed by a known means.

According to the fifth aspect of the present invention, the indexing shaft is provided so as to be rotatable relative to the main shaft through the main shaft, and one end thereof is in contact with the gripping means. A phase indexing device is provided at the other end of the indexing shaft to determine the phase of the gripping means.

As described above, the auxiliary shaft is provided, and the brake means and the encoder are attached to a portion different from the main shaft.
The phase indexing device can be easily attached to the other end of the main shaft.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a grinding device 12 having a spindle device 10 according to the present embodiment has a bed 14. A table 16 is provided on the bed 14. The table 16 has a ball screw 18
, And can be moved in the left-right direction on the paper by the table movement servomotor 19.

On the table 16, a spindle device 10 is arranged on both sides with a crankshaft W as a workpiece interposed therebetween. A hydraulic chuck 22 is provided at the tip of the main shaft 20 of the main shaft device 10, and the hydraulic chuck 22 holds the journals J at both ends of the crankshaft W and rotates the crankshaft W.

The bed 14 is provided with a ball screw 26 which is turned by a moving servomotor 24. The ball screw 26 is screwed with a female thread portion (not shown) of the grinding wheel head 28, and makes the grinding wheel head 28 move back and forth in the cutting direction by turning.

Further, a grindstone 32 rotated by a grindstone motor (not shown) is arranged on the grindstone head 28 at a position orthogonal to the crankshaft W, and moves back and forth with the grindstone head 28 to grind the crankpin P. It is supposed to.

FIGS. 3 and 4 show details of the spindle device 10. Since the left and right spindle devices 10 have the same configuration, they will be described with the same reference numerals.

A housing 34 of the spindle device 10 is fixed to the table 16 (see FIG. 1). In the housing 34, static pressure bearings 36 and 38 are arranged, and the main shaft 20 is rotatably supported.

A hydraulic chuck 22 is provided at the tip of the spindle 20.
Is installed. Receiving part 40 supporting journal J of crankshaft W at the eccentric position of hydraulic chuck 22
Is provided. A crank arm 42 is provided so as to face the receiving portion 40.
Is driven by a piston 46 moving in the cylinder 44, and grips the journal J with the receiving portion 40.

An indexing shaft 48 is provided at the center of the main shaft 20.
Are rotatably inserted. The rear end of the indexing shaft 48 penetrates a gear 50 fixed to the rear end of the main shaft 20, and the gear 52 constituting the phase indexing device 96 is fixed to the rear end. The gear 52 meshes with the gear 54. A transmission shaft 56 is concentrically rotatably mounted on the gear 54.

A gear 58 that meshes with the gear 50 is fixed to one end of the transmission shaft 56. The output member 62 of the differential device 60 having a speed reduction function is coupled to the gear 58. The rotation shaft of a phase index motor 66 is connected to the input member 64 of the differential device 60. further,
The other end of the transmission shaft 56 is connected to a revolving and rotating planetary gear mechanism (not shown) of the differential device 60.

On the other hand, an engagement pin 68 is provided at the tip end of the index shaft 48. The engaging pin 68 is urged forward and backward by a spring 70 so as to be able to engage with an engaging hole 72 formed on an end face of the journal J.

Thus, when the indexing shaft 48 rotates,
When the engagement pin 68 is engaged with the engagement hole 72, the engagement is performed, and the phase of the index shaft 48 is transmitted to the crankpin P.

On the right side of the housing 34, a built-in motor 74 is mounted. The built-in motor 74 includes a rotor 76 fixed to the main shaft 20 and a stator 78 arranged so as to surround the outer periphery of the rotor 76, and directly applies a rotational force to the main shaft 20.

Further, a housing 80 is formed in the center of the housing 34. A large-diameter transmission gear 82 fixed to the center of gravity of the main shaft 20 is located in the storage section 80. The transmission gear 82 meshes with a gear 86 fixed to a substantially central portion of the auxiliary shaft 84.

The auxiliary shaft 84 is arranged in parallel with the main shaft 20, and both ends thereof are rotatably supported by bearings 88 and 90. An electromagnetic brake 9 for stopping the auxiliary shaft 84 (main shaft 20) abnormally is provided at one end of the auxiliary shaft 84.
An encoder 94 for detecting the rotational angle position of the auxiliary shaft 84 (main shaft 20) is attached to the other end of the motor.

Next, the operation of the spindle device according to this embodiment will be described.

When a machining command is given while the journal J of the crankshaft W is mounted on the hydraulic chuck 22, the phase indexing motor 66 rotates forward, and the differential device 60
The indexing shaft 48 is rotated in the forward direction via the gears 52 and 54.

When the engagement pin 68 is engaged with the engagement hole 72 by the rotation of the index shaft 48, the crankshaft W starts to rotate integrally with the index shaft 48. The fact that the phase indexing motor 66 has been rotated by a predetermined angle indicates that the encoder 9
4, the phase index motor 66 is stopped.

In this state, the crank arm 42 of the hydraulic chuck 22 is driven to hold the journal J between the hydraulic chuck 22 and the receiving portion 40. Next, when the phase indexing motor 66 is reversed, the load current of the phase indexing motor 66 increases because the indexing shaft 48 is locked by the engaging pin 68.

This current increase is detected by a current detection circuit,
When the load current exceeds a certain value, the phase index motor 66 is stopped, and the detection signal of the encoder 94 at this time is updated as the origin signal.

In this manner, the phase of the specific crankpin P on the crankshaft W is determined on the rotation axis of the main shaft 20. Here, the built-in motor 74 is driven,
Grinding of the crankpin P is started.

At this time, if the built-in motor 74 becomes out of control due to a failure for some reason, the electromagnetic brake 92 is operated and the rotation of the main shaft 20 is stopped mechanically in order to prevent the torsion of the crankshaft W.

Since the electromagnetic brake 92 is disposed in parallel with the main shaft 20 and is provided at the end of the auxiliary shaft 84 whose speed is increased in relation to the gear ratio, a large braking force is exerted even with a small brake. In addition, since the electromagnetic brake 92 is provided separately from the main shaft 20, maintenance and inspection work of the electromagnetic brake 92 is facilitated. Further, by braking the center of gravity of the main shaft 20, the torsion of the main shaft 20 at the time of braking can be prevented. Since it can be attached to the other end of the auxiliary shaft 84, there is no need to use a specially shaped encoder, and maintenance and inspection work is performed.

Further, since it is located at a position close to the hydraulic chuck 22, the detection error of the rotation angle due to the twist of the main shaft 20 can be reduced.

[0041]

According to the first aspect of the present invention, it is sufficient to use a braking device having an appropriate capacity without using a large-diameter braking device. Further, the total length of the main shaft can be shortened, and the maintenance and inspection work of the brake means becomes easy.

According to the second aspect of the present invention, a general-purpose encoder can be used, and maintenance work can be facilitated. According to the third aspect of the invention, it is possible to reduce a detection error of the rotation angle due to the twist of the main shaft.

According to the fourth aspect of the invention, the rotational force of the main shaft can be transmitted to the auxiliary shaft with high accuracy. By increasing the number of rotations of the main shaft by setting the number of gear teeth, the rotation angle of the main shaft can be detected with high accuracy without using a high-resolution encoder, and the braking force of the brake means also increases. .

According to the fifth aspect of the present invention, the phase indexing device can be easily attached to the other end of the main shaft.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a grinding device including a spindle device according to an embodiment.

FIG. 2 is a perspective view showing a grinding device provided with a spindle device according to the embodiment.

FIG. 3 is a cross-sectional view showing a main part of the spindle device according to the embodiment.

FIG. 4 is a cross-sectional view showing a brake and an encoder part of the spindle device according to the embodiment.

FIG. 5 is a perspective view showing a conventional grinding device.

[Explanation of symbols]

 Reference Signs List 20 main shaft 22 hydraulic chuck (gripping means) 48 indexing shaft 74 built-in motor (motor) 82 transmission gear (transmission means) 84 auxiliary shaft 86 gear (transmission means) 92 electromagnetic brake (brake means) 94 encoder 96 phase indexing device

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Hisashi Kobayashi 1-1-1, Asahi-cho, Kariya-shi, Aichi Toyota Machine Works Co., Ltd. (72) Inventor Miki Mizuno 1-1-1, Asahi-cho, Kariya-shi, Aichi Toyoda Toyota F term (reference) 3C034 AA01 AA13 AA19 BB01 DD20

Claims (5)

[Claims] 1. A main shaft rotatably supported, gripping means provided at one end of the main shaft, a motor for directly rotating the main shaft, and an auxiliary shaft rotatably supported in parallel with the main shaft. And a transmission unit for transmitting rotation of the main shaft to the auxiliary shaft, and a brake unit provided at one end of the auxiliary shaft. 2. The spindle device according to claim 1, further comprising an encoder provided at the other end of the auxiliary shaft. 3. The spindle device according to claim 2, wherein the transmission unit is disposed near the holding unit of the spindle. 4. The spindle device according to claim 1, wherein the transmission means is a gear mechanism that increases the rotation speed of the spindle and transmits the speed to the auxiliary shaft. 5. An indexing shaft which penetrates the main shaft and is rotatable relative to the main shaft, one end of which is in contact with the gripping means, and a phase of the gripping means provided at the other end of the indexing shaft. The spindle device according to any one of claims 1 to 4, further comprising: a phase indexing device for determining the motor speed, wherein the motor is disposed at an intermediate portion of the spindle.