JPH0321884Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) This invention relates to a position indexing device.

(Prior Art) Conventionally, devices with various structures have been used for position indexing of rotary tables and the like of machine tools. For example, a specific example thereof is a device described in Utility Model Application No. 1982-60407, an earlier application by the present applicant. In this device, as shown in FIG.
A flow direction control valve 84 is interposed between a discharge line 82 and a tank line 83 connected to a drive motor 81 that drives the 0, and a spool 85 that opens and closes a variable orifice is provided therein. Then, by bringing a contact 87 connected to the spool 85 into contact with the cam surface of a cam 86 that is interlocked with the rotation of the drive motor 81, the spool 85 is slid in accordance with the cam shape, and the variable orifice is moved. Adjust the opening. On the other hand, a recess 88 is formed in the cam surface, and when the contact 87 is fitted into the recess 88, the spool 85 closes the variable orifice and stops supplying fluid to the drive motor 81. , the position is determined.

The flow direction control valve 84 has a spring chamber 92 and a pilot chamber 93, and the discharge line 82 has a spring chamber 92 and a pilot chamber 93.
and a tank line 83 are also connected to the spring chamber 92 and the pilot chamber 93 via a forward/reverse switching valve 89, respectively. Further, the fluid pressures of the discharge line 82 and the tank line 83 are also supplied to a hydraulic cylinder 96 for moving the indexed object 80 up and down through lines 94 and 95 via the flow direction control valve 84. There is. A lower surface of the indexed object 80,
Rings 98 and 99 are attached to the upper surface of the base 97 that supports the indexed object 80, respectively, and coupling teeth that engage with each other are formed on opposing surfaces of these rings 98 and 99. There is. The indexed object 8 is rotated by the hydraulic cylinder 96.
0 is lowered and the rings 98 and 99 are brought into an occlusal state, the object to be indexed 80 is mechanically fixed at a predetermined indexed position, that is, the position is fixed. There is. Note that an electromagnetic switching valve 100 for switching the drive motor 81 between forward and reverse rotation is interposed in the connection line to the drive motor 81.

When performing position indexing in the above device, the switching valve 89 is first moved to the switching position. Then, the pilot chamber 93 of the flow direction control valve 84
The pressure fluid is guided to the spool 85.
is pushed toward the rear spring chamber 92 side, and the contact 87
is removed from the recess 88 on the cam surface. Further, the flow rate directional control valve 84 is located at the symbol position S2, and the communication state between the inlet ports P and T and the outlet ports A and B is switched. As a result,
The connection state between the discharge line 82 and the tank line 83 and the hydraulic cylinder 96 is reversed, and the object 80 to be indexed, which had been located at the lowered position, is raised, and the rings 98 and 99 are disengaged, and the position The stationary state is released. Thereafter, by switching the electromagnetic switching valve 100 from the neutral position to, for example, the normal rotation side position, a circuit is formed in which the working fluid circulates through the drive motor 81 via the flow direction control valve 84, and the drive motor 81 is driven to rotate. and drives the object 80 to be indexed. Then, after a predetermined period of time has elapsed from the above, if the switching valve 89 is returned to the neutral position, the discharge line 8
The second fluid is led to the spring chamber 92 of the flow rate direction control valve 84, and the spool 85 is pushed toward the cam 86 at the tip by this fluid pressure and the spring force, and the contact 87 responds to this force. But hold it and press it against the cam surface.
will come into contact. In this state, the flow direction control valve 84 is located at the symbol position S3, the variable orifice is slightly constricted, and the drive motor 81 is decelerated. When the contact 87 of the spool 85 reaches the position of the recess 88 on the cam surface and is fitted into the recess 88, the flow direction control valve 84 is located at the symbol position S1, and the line leading to the drive motor 81 is connected to the tank. line 83
By opening the drive motor 81, the drive motor 81 is stopped and the position indexing of the indexed object 80 is completed. Also,
At this time, the hydraulic pressure supply state to the hydraulic cylinder 96 is reversed again, and the hydraulic cylinder 9
6, the indexed body 80 is lowered, and the rings 98,
99 is brought into the occlusal state, and the object to be indexed 80 is fixed at the indexed position.

(Problems to be Solved by the Invention) As explained above, in the conventional device, at the start of the indexing operation, the forward/reverse switching valve 89 is first switched, and then the pilot chamber 93 of the flow direction control valve 84 is switched. switching of the communication state in the flow direction control valve 84 by moving the spool 85, switching of the pressure supply state to the hydraulic cylinder 96, raising and stopping of the indexed object 80 by the hydraulic cylinder 96. After going through the steps of canceling the steady state and switching the electromagnetic switching valve 100, the driving of the indexed object 80 by the drive motor 81 is started.
From the start operation given to the forward/reverse switching valve 89 until the index drive by the drive motor 81 actually starts, time is required for each of the above steps to be executed sequentially. For example, after the spool 85 of the flow direction control valve 84 moves, until the indexed object 80 actually starts to rise by the hydraulic cylinder 96, the upper surface of the piston inside the hydraulic cylinder 96 has been pressurized. High-pressure fluid is discharged, and at the same time, high-pressure fluid flows into the lower surface of the piston inside the cylinder chamber.
It is necessary that this is filled until it has enough force to overcome the weight of the object 80 to be indexed. In this way, there is a time delay due to the flow of the working fluid until the pressure state required for each operation is reached in each of the above steps, and the above time delay is caused by the time required for moving the actuator in each step. Since it is accumulated for each step, there was a problem that it lacked quick response at startup.

This invention was made in order to solve the above-mentioned conventional problems, and its purpose is to drive the indexed object using a hydraulically operated drive motor and to split the indexed object using a hydraulic cylinder. It is an object of the present invention to provide a position indexing device that is fixed at an extended position and can improve startup responsiveness at the start of an indexing operation.

(Means for solving the problem) Therefore, the position indexing device of this invention
A pilot type directional control valve 24 is interposed between a discharge line 51 and a tank line 52 that are connected to the drive motor 1 that drives the The position fixing port 13 and the position fixing release port 14 of the hydraulic cylinder 12 are connected to the discharge line 51 and the tank line 52 via lines 63 and 64 so as to be switchable and communicable, and the pilot type direction switching When the valve 24 is located at the neutral position S1, working fluid is supplied from the one line 63 to the position fixing port 13 of the hydraulic cylinder 12, and the hydraulic cylinder 12 fixes the position of the indexed object 6. is carried out, and the supply of working fluid to the drive motor 1 is stopped. On the other hand, when the pilot type directional control valve 24 is located in the switching position S2, S3, the hydraulic cylinder 12 is supplied from the other line 64.
The hydraulic cylinder 12 is configured to supply working fluid to the position release port 14 to release the position fixation by the hydraulic cylinder 12, and to circulate the working fluid to the drive motor 1. The above discharge line 5 is connected to the pilot chamber 45 of the valve 24.
A branch line 74 branching from C1 is connected via a switching valve 58, and the switching valve 58 is set to the first switching position C1.
When the fluid in the discharge line 51 is introduced into the pilot chamber 45, the pilot type directional switching valve 24 is switched to the switching positions S2 and S3, and the switching valve 58 is switched to the second switching position C2. After switching, the position indexing device is configured such that the pilot type directional switching valve 24 remains in the switching position until the indexed body 6 reaches the indexed position, and the position indexing device is configured such that the switching position state of the pilot type directional switching valve 24 continues until the indexed body 6 reaches the indexing position, and The side port is connected by a bypass line 76 to the position release port 14 to which working fluid is supplied when the position of the hydraulic cylinder 12 is released, and the position release port 14 is connected to the bypass line 76. A check valve 77 is provided to allow fluid flow in this direction.

(Function) In the position indexing device configured as described above, the switching valve 58 is moved to the first switching position C in order to start the indexing operation.
1, the fluid in the discharge line 51 is guided to the pilot chamber 45, and at the same time, the position release port of the hydraulic cylinder 12, which had been in a low pressure state for positioning the indexed object 6, is released. 14
High pressure fluid is supplied to the bypass line 76. In conventional equipment, pilot type directional control valve 1
The supply of the high-pressure fluid was started after the switching operation in step 2 was performed, but in this device, the switching operation is started through the bypass line 76 without waiting for the switching operation of the pilot type directional switching valve 24. Since high-pressure fluid is supplied immediately after the switching operation of the valve 58, the operation to release the position fixing of the hydraulic cylinder 12 is quickly performed, and therefore, the actual indexing start operation to the switching valve 58 can be quickly performed. The time required for the drive motor 1 to start driving is shortened, and responsiveness at startup can be improved. Note that when the switching valve 58 is switched to the second switching position C2 after startup, if the pressure on the switching valve 58 side of the bypass line 76 is low, the check valve 77 causes the hydraulic cylinder 12 side to be switched to the second switching position C2. Since the flow of fluid from the pilot type directional control valve 24 to the switching valve 18 side is blocked, high pressure fluid continues to act on the position release port 14 of the hydraulic cylinder 12 from the pilot type directional switching valve 24, so that the position The fixed release state is maintained, and the indexing operation similar to the conventional device continues.

(Example) Next, a specific example of the position indexing device of this invention will be described in detail with reference to the drawings.

FIG. 2 is a partially cutaway front view of the position indexing device in one embodiment of this invention, and in the same figure, 1
is a double-shaft drive motor having low speed and high torque characteristics, such as a trochoid motor or a gear motor, and has a drive gear 5 attached to its upper main shaft 2. The object 6 to be indexed, such as a rotary table, has a rotating shaft 7
and a gear 8 which is fixed to the rotating shaft 7 and meshes with the driving gear 5, and when the upper main shaft 2 rotates, the driving gear 5, the gear 8, and the rotating shaft 7 are connected to each other. The indexable body 6 can be rotationally driven. Further, the rotating shaft 7 is
It can move up and down with respect to a base 9 that supports it, and rings 10 and 11 are attached to the upper surface of the base 9 and the lower surface of the indexed object 6, respectively, and the opposing surfaces of these rings 10 and 11 Coupling teeth are formed that engage with each other. The rotating shaft 7 is moved up and down by a hydraulic cylinder 12.

A cam 22 is attached to the lower main shaft 3 of the drive motor 1.
is attached. And as shown in Figure 3,
The cam 22, the dogleg-shaped lever 23 that swings in accordance with the shape of the cam 22, and the flow rate that controls the flow rate and direction of the fluid supplied to the drive motor 1 in accordance with the swing of the lever 23. The direction control valve 24 constitutes a position indexing mechanism. Above cam 2
As shown in FIG. 3, reference numeral 2 is a substantially disk-shaped member disposed concentrically with the axis of the lower main shaft 3, and the circumferential side thereof has an arc-shaped portion 32 concentric with the lower main shaft 3. It has two substantially tapered portions 30 that gradually go toward the center of the arcuate portion 32 and a recessed portion 31 that is located approximately at the center of the tapered portion 30. The lever 23 is rotatably supported at its midpoint by the casing 20, and a roller 36 is rotatably supported at the tip of an arm 33 extending downward in the figure from the pivot point. . This roller 3
6 can roll on the circumferential side of the cam 22. Note that the recess 3 provided in the cam 22
1 is a shape into which the roller 36 can be fitted. The tip of the arm 34 of the lever 23, which extends upward in the figure, is pivotally connected via a pin to a rod 37 that is integrally formed at the tip of the spool of the flow direction control valve 24.

Next, the flow rate directional control valve 24 will be explained with reference to FIG. 1. The flow rate directional control valve 24 supplies water to the drive motor 1 by sliding a spool 42 extending into the main body. A pump port P is connected to a discharge line 51 that controls fluid and is connected to a hydraulic pump (not shown).
and a tank port T connected to the tank line 52, and further has three ports A, B, and M on the secondary side. In addition, the spool 42
A spring chamber 44 having a spring 43 is provided at the rear end (right side in FIG. 1). Also, this spring chamber 44
A pilot chamber 45 is provided on the opposite side, and when fluid is introduced into this pilot chamber 45, the fluid pressure in this pilot chamber 45 and the spring 4
The spring force of No. 3 is made to face each other. In the neutral state where the spool 42 has moved to the most distal end side, it is located at the symbol position S1, the pump port P communicates with the port A, the tank port T communicates with the port B, and the port M is blocked. In the switching state, the communication state shown in symbol positions S2 and S3 is given,
First, when the spool 42 is in the most retracted state, it is located at the symbol position S2, and the pump port P
is connected to port B, tank port T is connected to ports A and M
communicate with each other. Further, in the process of the spool 42 gradually moving toward the tip side from this state, it is located at the symbol position S3, and the flow path is gradually narrowed.

Port A of the flow rate direction control valve 24 is connected by a line 63 to a position fixing port (hereinafter referred to as a downward pressure supply port) 13 of the hydraulic cylinder 12 that moves the indexed object 6 up and down. On the other hand, port B is connected by a line 64 to a position release port (hereinafter referred to as release port) 14 which becomes a high pressure side when the hydraulic cylinder 12 is raised, that is, when the position is released. Further, a pressure fluid outlet port 15 of the hydraulic cylinder 12 that internally communicates with the release port 14 within the cylinder and a port M of the flow direction control valve 24 are connected to a line 65,
It is connected to the drive motor 1 via 66. An electromagnetic switching valve 67 for switching the drive motor 1 between forward and reverse rotation is interposed in the lines 65 and 66. Port M and port T of the flow direction control valve 24 are connected by a bypass line 71 in which a throttle 72 is provided.

On the other hand, the discharge line 51 and the tank line 5
Switching valve 5 is connected to branch lines 74 and 75 branched from 2.
The inlet ports P and T of the switching valve 58 are connected, and the outlet ports A and B of the switching valve 58 are connected to the pilot chamber 45 and spring chamber 44 of the flow rate directional control valve 24 through pilot lines 56 and 57. are doing. Furthermore, the pilot line 56 leading to the pilot chamber 45 and the line 64 leading to the release port 14 of the hydraulic cylinder 12 are connected via a bypass line 76, and the bypass line 76 is connected from the switching valve 58 side. A check valve 77 is provided to allow flow in the direction toward the release port 14.

Next, the operating state of the above-mentioned position indexing device will be explained. First, the roller 36 provided on the lever 23
is fitted into the recess 31 of the cam 22, and the drive motor 1
A state in which the motor is stopped at the index rotation position will be explained. In this case, it is assumed that the switching valve 58 is located at the second switching position in FIG. Further, the electromagnetic switching valve 67 is also positioned at a neutral position. In this state, the spool 42
is pressed toward the distal end by the force of the spring 43 and the fluid pressure within the spring chamber 44. This force is transmitted to the roller 36 via the rod 37 at the tip of the spool 42 and the lever 23, and the roller 36 is fitted into the recess 31 of the cam 22. Moreover, in this way, the flow direction control valve 24 is in the neutral position,
That is, since it is located at the symbol position S1, the fluid in the discharge line 51 is transmitted from the port A through the line 63 to the pressure-reducing pressure supply port 13 of the hydraulic cylinder 12, and the release port 14 is connected to the tank through the line 64. The indexed body 6 is pushed down and the coupling teeth provided on the indexed body 6 side and the base 9 side are engaged with each other to mechanically fix the indexed position. state, that is, stationary. On the other hand, since the lines 65 and 66 leading to the drive motor 1 are both open to the tank line 52, no fluid is supplied to the drive motor 1, and the drive motor 1 is held in a stopped state.

When performing position indexing from the above state, first the switching valve 58 is switched to the first switching position indicated by the symbol position C1 in FIG. When the switching valve 58 is positioned in the first switching position in this way,
The fluid in the discharge line 51 is transferred to the pilot line 56.
to the pilot chamber 45, while the spring chamber 44 is opened to the tank line 52 via the pilot line 57. At the same time, the high pressure fluid in the discharge line 51 is transferred to the hydraulic cylinder 12.
Release port 1, which had been in a low pressure state until then,
4, the lower surface of the piston inside the hydraulic cylinder 12 and the inside of the line 65 communicating therewith are brought into a high pressure state. Therefore, by supplying high-pressure fluid to the pilot chamber 45, the spool 42 starts moving, and during the movement, for example, at the symbol position S3, the hydraulic cylinder 12
When the downward pressure supply port 13 communicates with the tank port T and the previously high fluid pressure is released, the upward movement of the hydraulic cylinder 12 is started, and as a result, the period of switching movement of the spool 42 and At the same time, the hydraulic cylinder 12 quickly releases the indexed object 6 from its position.

On the other hand, as the spool is switched, the lever 23 rotates, and the roller 36 escapes from the recess 31. Furthermore, as a result of the movement of the spool 42 in this way, the flow direction control valve 24 is moved to the symbol position S2.
The discharge line 51 is connected to the port B via the pump port P, and at this time, the fluid in the discharge line 51 is also supplied to the release port 14 of the hydraulic cylinder 12 via the line 64. The Rukoto. Further, since the downward pressure port 13 is opened to the tank line 52 through the line 63, the lock release operation continues. Then, the electromagnetic switching valve 67 is set to the forward rotation position in response to the unclamping completion signal transmitted upon completion of the lock release operation, and the pressure fluid flowing out from the pressure fluid outlet port 15 of the hydraulic cylinder 12 is routed through the line 65. Since the other line 66 communicates with the tank line 52 through the port M, the drive motor 1 rotates rapidly, and as a result, the indexed object 6 is rotationally driven.

Then, after a predetermined period of time has elapsed, the switching valve 58 is returned to the second switching position again. This return operation is
This may be done by switching the switching valve 58 based on a signal output from an angle detector immediately before the indexing position, or by using a timer or the like. In this way, the switching valve 5
8 is placed in the second switching position, the fluid in the discharge line 51 is introduced into the spring chamber 44 again, and the pilot chamber 45 is communicated with the tank line 52, so that the spool 42 is connected to the fluid in the spring chamber 44. The lever 23 is moved toward the tip side by pressure and the force of the spring 43.
trying to rotate. However, the above lever 2
Since the arcuate portion 32 of the cam 22 is located at the position of the roller 36 at the tip of the cam 22, the roller 36
contacts this arcuate portion 32 and rolls. As a result, the spool 42 of the flow rate directional control valve 24 is held at an intermediate position without moving to the most extreme position. In this manner, when the flow direction control valve 24 is located at the symbol position S3, its flow path is constricted, and therefore the flow rate of the fluid sent to the drive motor 1 is reduced, and the indexed body 6 is rotated. It is driven at a slower speed than at the beginning.
Also, at this time, the bypass line 76 is communicated with the tank line 52 by the switching valve 58 switched to the second switching position, but this low pressure is blocked by the check valve 77, and the release port of the hydraulic cylinder 12 is 14, the indexed object 6 continues to be in the unlocked state.

As the drive motor 1 continues to rotate,
The flow path is further narrowed by the substantially tapered portion 30 of the cam 22, and the rotational speed of the drive motor 1 is reduced. Thereafter, when the recess 31 of the cam 22 is located at the position of the roller 36, the roller 36 is fitted into the recess 31, and the flow direction control valve 24 is again moved to the neutral position S.
Located at 1. At this time, the fluid pressure supply state to the hydraulic cylinder 12 is reversed, the indexed body 6 is pushed down, and the coupling teeth provided on the indexed body 6 side and the base 9 side are engaged with each other, and the indexed body 6 is pushed down. 6 is fixed at the indexed position. At this time, as described above, the line 66 leading to the drive motor 1 is opened to the tank line 52 through the bypass line 71, and the line 65 is also connected from the port 15 of the hydraulic cylinder 12 through the port 14 to the line 64.
Since the tank line 52 is opened to the tank line 52, the driving of the drive motor 1 is stopped. In addition, in the present application, positioning refers to, in order to ensure positioning accuracy at the indexed position or to ensure the stopped state of the indexed object, for example, by bringing the coupling teeth into the occlusal state, as described above, This refers to mechanically fixing the position of the indexed object.

As explained above, in the above embodiment,
The release port 14 of the hydraulic cylinder 12 which is in the fixed position operation state is in communication with the tank line 52 and is in a low pressure state, but in order to start the indexing operation, the switching valve 58 is switched to the first switching position. in some cases,
High pressure fluid is supplied from the bypass line 76 to the release port 14 without waiting for the completion of the switching operation of the pilot type flow directional control valve 24. Therefore, compared to the case where the pressure fluid is supplied to the port 14 after the switching operation of the pilot type flow directional control valve in the conventional device, in the above embodiment, the pressure fluid is supplied to the port 14 at the same time as the switching operation of the pilot type flow directional control valve 24. Since the pressure fluid is supplied to the supply port 14, it is possible to improve the responsiveness at the time of startup.

An example of this invention has been described above,
The position indexing device of this invention is not limited to the above embodiments, but can be implemented with various modifications. For example, in the above embodiment, in order to decelerate the rotation of the drive motor 1 near the index position, a pilot type flow directional control valve 24 having a variable orifice is used.
However, if the object to be indexed has a small inertia and does not require a deceleration function, a pilot type directional control valve may be used. Further, in the above-described position indexing mechanism, if it is necessary to perform position indexing at a larger number of points, a plurality of recesses corresponding to the indexed positions may be provided on the cam circumferential side. In addition to the above-mentioned double-shaft drive motor, a drive motor having one main shaft is used as the drive motor, and the object to be indexed is driven by this main shaft. A cam may also be installed.

(Effect of the invention) As explained above, in the position indexing device of this invention, when the switching valve is switched to the switching position to start the indexing operation, the fixed position of the indexed object is released. Since the supply of high-pressure fluid to the hydraulic cylinder for this purpose is carried out without waiting for the switching operation of the pilot type directional switching valve that occurs after switching of the switching valve, the above-mentioned position fixing release operation can be performed quickly and As a result, it is possible to improve the responsiveness when starting the indexing operation.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an example of the position indexing device of this invention, FIG. 2 is a partially cutaway front view of the position indexing device, FIG. 3 is a cross-sectional view taken along the line of FIG. 2, and FIG. The figure is a circuit diagram for explaining a conventional device. 1... Drive motor, 6... Indexed object, 12...
Hydraulic cylinder, 13... Pressure supply port during descent (position fixing port), 14... Release port (position fixing release port), 24... Flow rate directional control valve (pilot type directional control valve), 45... pilot room,
51...Discharge line, 52...Tank line, 5
8...Switching valve, 74...Branch line, 76...Bypass line, 77...Check valve.

Claims (1)

[Scope of utility model registration request] A pilot type directional control valve 24 is interposed between a discharge line 51 and a tank line 52 connected to the drive motor 1 that drives the indexed object 6, and outlet side ports A and B of this pilot type directional control valve 24 are provided.
The position fixing port 13 and the position fixing release port 14 of the hydraulic cylinder 12 are connected to the discharge line 51 and the tank line 52 via a pair of lines 63 and 64 so as to be switchable and communicable. When the pilot type directional control valve 24 is located at the neutral position S1, working fluid is supplied from the one line 63 to the position fixing port 13 of the hydraulic cylinder 12 so that the hydraulic cylinder 12 can control the indexed object. 6 is fixed in position, and the supply of working fluid to the drive motor 1 is stopped. On the other hand, when the pilot type directional control valve 24 is located at the switching positions S2 and S3, fluid is discharged from the other line 64. The hydraulic cylinder 12 is configured to supply working fluid to the position release port 14 of the hydraulic cylinder 12 to release the position fixing by the hydraulic cylinder 12, and to circulate the working fluid to the drive motor 1. A branch line 74 branching from the discharge line 51 is connected to the pilot chamber 45 of the directional switching valve 24 via a switching valve 58, and the switching valve 58 is switched to the first switching position C1 to discharge the discharge into the pilot chamber 45. When the fluid in the line 51 is introduced, the pilot type directional control valve 24 is moved to the switching position S2,
After switching to S3 and switching the switching valve 58 to the second switching position C2, the pilot type directional switching valve 24 is kept in the switching position until the indexed object 6 reaches the indexing position. In this position indexing device, the outlet side port of the switching valve 58 is connected by a bypass line 76 to the position release port 14 to which working fluid is supplied when the position of the hydraulic cylinder 12 is released. A position indexing device characterized in that a check valve 77 is connected to the bypass line 76 and is connected to the bypass line 76 to allow fluid to flow in the direction of the position release port 14.