JPS6248082B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is for converting an electrical signal into a relatively large amount of mechanical operation, and is applicable to various industrial machinery fields including computer-controlled hydraulic robots. The present invention relates to an electromechanical conversion device that can be suitably used.

[Conventional technology]

For example, in order to promote computer control of hydraulic equipment, it is first necessary to develop a device that converts an electrical signal into a proportional mechanical operation amount without using complicated equipment such as electric/oil servo valves. It is.

As a prior art related to such a device, one disclosed in Japanese Patent Application Laid-open No. 125986/1986 is known. In other words, this motor has a force motor that converts an input electrical signal into a small amount of displacement at the output end that can move back and forth in the axial direction, and a pair of fluid introduction chambers with the axis perpendicular to the axis of the force motor. The output piston is provided with an output piston that is disposed in and moves forward and backward in the axial direction according to the pressure difference between the two fluid introduction chambers. A taper cam is fixed to the output shaft of the piston, or one engagement end of the L-shaped link is engaged, and the amount of displacement of the cam surface of the taper cam or the other engagement end of the L-shaped link,
A spool-type pilot valve is operated according to the amount of displacement of the output end of the force motor, and the piston can be operated in proportion to the output end of the force motor.

[Problem that the invention seeks to solve]

However, when the force motor and the output piston are arranged perpendicularly to each other in this way, a taper cam or an L-shaped link as described above is used to reduce the piston's operating amount to a small displacement amount and provide feedback to the pilot valve. must be used. Therefore, by changing the deceleration rate, the ratio of the amount of piston operation to the amount of displacement of the force motor,
In other words, there is a problem in that it is difficult to configure the device so that the ratio of output to input can be adjusted.

In other words, in order to be able to adjust the deceleration rate of a tapered cam, it is necessary to make it possible to replace it with a cam with a different slope, or to install a mechanism inside the cam to change the slope of the cam surface. However, the former requires time and effort to adjust, and the latter has the problem of complicating the structure. Further, in any of these, when the deceleration rate is adjusted, the height of the cam surface changes, so it is often necessary to readjust the relative mounting position of the piston and the force motor.

On the other hand, in order to make it possible to change the deceleration rate in a link that uses an L-shaped link, it must be possible to change the distance from the fulcrum of the link to one engagement point, or from the fulcrum to the other engagement point. . However, when changing any of these distances, the relative mounting positions of the piston and the force motor must be changed accordingly. Therefore, it is very difficult to easily adjust the ratio of the amount of piston operation to the amount of displacement of the force motor.

The present invention aims to eliminate all such problems.

[Means for solving problems]

In order to achieve such an object, the present invention arranges a force motor and a piston with their axes parallel to each other, and has a proximal end attached to a pivot member that can be screwed back and forth in a direction perpendicular to each axis. The tip of a retractable feedback rod having a pivotally supported portion is engaged with the piston, and the movement of the intermediate portion of the food back rod is used as feedback information to move the piston to a position corresponding to the output end of the force motor. It is characterized by being configured so that it can be controlled.

That is, the electromechanical conversion device according to the present invention includes a force motor that converts an input electric signal into a small displacement amount of an output end that can move back and forth in the axial direction;
An output piston whose axis is positioned parallel to the axis of this force motor and which is arranged between a pair of fluid introduction chambers and moves forward and backward in the axial direction according to the pressure difference between the two fluid introduction chambers, and this piston. and a pivot member held so that it can be screwed back and forth in a direction perpendicular to the axis of the force motor; an extendable feedback rod facing the output end of the force motor;
A fluid control mechanism that selectively supplies pressurized fluid to either one of the fluid introduction chambers by comparing the displacement amount of the intermediate portion of the feedback rod with the displacement amount of the output end opposite to this displacement amount. The piston is characterized in that the piston outputs an amount of operation proportional to the input to the force motor.

[Effect]

With such a configuration, the amount of actuation of the piston is fed back as the amount of displacement of the intermediate portion of the feedback rod, and the difference between the amount of displacement and the amount of displacement at the output end of the force motor is canceled out. Actuation of the piston is controlled. Therefore, the piston can be operated in proportion to the amount of displacement of the output end of the force motor.

Moreover, if the length of the feedback rod is changed by screwing the pivot members back and forth, the ratio of the amount of displacement of the intermediate portion to the amount of operation of the tip of the feedback rod changes. Therefore, the ratio of output to input can be finely adjusted as appropriate.
Moreover, since this adjustment merely changes the position of the pivot point of the feedback rod, which is arranged perpendicularly to the respective axes of the piston and the force motor, the relative arrangement of the piston and the force motor is You can easily and precisely adjust the input and output ratios without any changes in position.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 (FIG. 1) A force motor 2 is attached to one side wall of a box-shaped housing 1 having a cavity 1a inside. The force motor 2 is a conventional force motor that converts an electric signal input to a terminal 2a into a small displacement amount in the axial direction of a drive shaft 2b, which is an output end. Further, a pair of cylinders 3, 3 having axes parallel to the drive shaft 2b of the force motor 2 are formed on both side walls of the bottom of the housing 1, and each cylinder 3,
Each end of the piston 4 is slidably fitted into the piston 3. That is, this piston 4 is arranged between the pair of fluid introduction chambers 5 and 6 formed in each of the cylinders 3 and 3, and both fluid introduction chambers 5,
It is designed to advance or retreat in the axial direction depending on the pressure difference within 6. An output shaft 7 is integrally protruded from the axial center of the end face of the piston 4, and the tip end of the output shaft 7 is made to project out of the housing 1 through a shaft hole 8. Further, within the cavity 1a of the housing 1, there is provided a feedback mechanism 9 for converting the amount of forward and backward movement of the piston 4 into a small amount of displacement. The feedback mechanism 9 includes a pivot member 11 that is screwed onto the top wall of the housing 1 and can be screwed back and forth in a direction perpendicular to the axis of the piston 4.
and the proximal end 12a is inserted into the concave portion 1 of the pivot member 11.
1a, and engages the distal end 12b with the engaging portion 4a of the piston 4 to provide the feedback rod 1.
2, and the axis of the drive shaft 2b of the force motor 2 intersects with the intermediate portion 12c of the feedback rod 12. The feedback rod 12 has a proximal end member 13 and a distal end member 14 fitted together in a telescopic manner so as to be expandable and retractable in the axial direction.
A spring 15 is interposed between 3 and 14 to bias these members 13 and 14 in the direction in which the feedback rod 12 extends. Further, the fluid is provided in one side wall of the housing 1 so that the amount of displacement of the drive shaft 2b of the force motor 2 and the amount of displacement of the intermediate portion 12c of the feedback rod 12 are compared and the difference is canceled out. Introduction room 5,
A fluid control mechanism 16 is provided for selectively supplying pressure fluid to either one of the two. Specifically, the fluid control mechanism 16 includes a through hole 17 formed in the side wall of the housing 1 so as to be aligned with the drive shaft 2b of the force motor 2, and a sleeve 18 arranged around the inner periphery of the through hole 7. The sleeve 18 is fitted so as to be slidable in the axial direction, and the spool 19 is fitted to the inner circumference of the sleeve 18 so as to be slidable in the axial direction. Three annular grooves 2 are formed on the inner peripheral surface of the through hole 17.
3, 24, 25 are formed at predetermined intervals in the axial direction, and the central annular groove 24 is communicated with a pressure fluid source 27 via a fluid passage 26, and the annular grooves 23, 25 on both sides are connected to a pressure fluid source 27. The fluid introduction chambers 5 and 6 are communicated through passages 28 and 29, respectively. In addition, ports 31, 32, 33 are bored in the peripheral wall of the sleeve 18 and communicate with the annular grooves 23, 24, 25, respectively.
1 and 33 are kept closed by the spool 19. Then, the spool 19 is fixed to the drive shaft 2b of the force motor 2, and a spring 34 is inserted between the spool 19 and the sleeve 18.
8 is brought into elastic contact with the intermediate portion 12c of the feedback rod 12. In addition, 3
5 is a space 3 in contact with both end surfaces of the spool 19;
6 and 37 are fluid passages for communicating with the oil tank 38.

Next, the operation of this embodiment will be explained.

When an electric signal is input to the terminal 1a of the force motor 1 and the drive shaft 1b is displaced by an amount corresponding to the electric signal, for example, to the left in the figure, the spool 19 is displaced to the left together with the drive shaft 2b. As a result, the ports 31 and 32 are brought into communication. Therefore, the pressure fluid introduced into the sleeve 18 from the pressure fluid source 27 through the fluid passage 26 flows from the port 31 through the fluid passage 28 into one fluid introduction chamber 5, and the piston 4 moves to the left.
Then, the sleeve is urged by the piston 4 to rotate to the left, and the sleeve 18, which is in elastic contact with the intermediate portion 12c of the rod 12, follows the spool 19 and moves to the left. Then, when the sleeve 18 catches up with the spool 19 and the port 31 is closed again by the spool 19, the piston 4 stops. Note that while the sleeve 18 and the spool 19 are relatively displaced and the port 31 is open, the fluid passage 29 and the fluid passage 35 are in communication via the port 33, so that the other fluid The fluid in the introduction chamber 6 is discharged to the oil tank 38 through both the fluid passages 29, 35. Also, on the contrary, force motor 1
When the drive shaft 1b is displaced to the right in the figure together with the spool 19, the ports 32 and 33 are brought into communication. Therefore, the pressure fluid introduced into the sleeve 18 from the pressure fluid source 27 through the fluid passage 26 flows from the port 33 into the fluid introduction chamber 6 through the fluid passage 29, and the piston 4 moves to the right. Then, the sleeve rotates to the right under the force of the piston 4, and the sleeve 18, which is in elastic contact with the intermediate portion 12c of the rod 12, follows the spool 19 and moves to the right. Then, when the sleeve 18 catches up with the spool 19 and the port 33 is closed again by the spool 19, the piston 4 stops. Note that while the port 33 is open, the fluid passage 28 and the fluid passage 35 are in communication via the port 31, so the fluid in the fluid introduction chamber 5 flows through both the fluid passages 29, 35. The oil is discharged to the oil tank 38.

According to such an embodiment, x is the displacement amount of the spool 19 that operates in proportion to the input electric signal, and y is the operation amount of the output piston 4.
Assuming that the distance from the base end 12a of the feedback rod 12 to the intermediate portion 12c is a, and the distance from the base end 12a of the feedback rod 12 to the tip 12b is b, the distance between them is x/ The relationship y=a/b holds true. In other words, the piston 4 operates proportionally with the movement of the spool 19 amplified. Therefore, with such a device, by inputting an electrical signal to the terminal 2a of the force motor 2, a relatively large mechanical output proportional to the electrical signal can be obtained from the output shaft 7 of the piston 4. It is something that can be done.

Furthermore, by screwing the pivot member 11 of the feedback mechanism 9 into and out of the housing 1, the distance b from the base end 12a to the tip 12b of the feedback rod 12 can be changed. can. Therefore, there is an advantage that the ratio of output to input, in other words, the amount of forward and backward movement of the output piston 4 in response to a specific input electrical signal can be adjusted as appropriate with a simple operation.
Furthermore, since this adjustment merely changes the position of the pivot point of the feedback rod 12, which is disposed perpendicularly to the axes of the piston 4 and the force motor 2, the piston 4 and the force motor 2 This can be carried out without any change in the relative installation position. Therefore,
The input and output ratios can be easily and accurately adjusted without complicating operations or complicating the structure.

Further, as in the illustrated embodiment, the fluid control mechanism 1
6 has a sleeve 18 and a spool 19, and the small displacement amount of the drive shaft 2b of the force motor 2 and the intermediate portion 12c of the feedback rod 12 are
If the fluid is switched by comparing the amount of small displacement of The advantage is that initial performance can be maintained over a long period of time.

Embodiment 2 (FIG. 2) In this device, contrary to the first embodiment, the sleeve 18 is fixed to the drive shaft 2b of the force motor 2, and the spool 19 is fixed to the intermediate portion 12c of the feedback rod 12. It was brought into ballistic contact with
It has the same effect as that of the first embodiment. Therefore, the same reference numerals are given to the same or corresponding parts as in the above embodiment, and the explanation thereof will be omitted.

Note that the fluid control mechanism is not limited to one consisting of a sleeve and a spool as shown in Embodiments 1 and 2 above, but for example, the sleeve may be eliminated and one end of the spool may be connected to the output end of the force motor via a spring. At the same time, the other end of the spool is brought into contact with the intermediate portion of the feedback rod via a spring, and the fluid is switched by the amount of displacement generated based on the pressing force acting on the spool from both springs. It may be something, etc.

〔Effect of the invention〕

Since the present invention has the above configuration, it is not only possible to cause the piston to output a mechanical operation amount proportional to the electric signal input to the force motor, but also to centralize the ratio of the output to the input. It can be finely changed as needed by adjusting the screwing forward and backward movement of the support members. Therefore, it is possible to change the output only by mechanical operation without changing the gain on the input side, and the degree of freedom in adjustment can be increased.

In addition, input and output can be controlled by arranging the axis of the force motor and the axis of the piston in parallel, and by changing the position of the pivot point of the feedback rod, which is arranged perpendicular to these axes. Since the ratio can be adjusted, the adjustment can be performed without changing the relative mounting positions of the piston and the force motor.
Therefore, it is possible to easily and accurately adjust the input and output ratios without complicating operations or complicating the structure, making it possible to quickly and accurately adjust the adjustment work required when making initial settings or changing specifications. An excellent effect can be obtained by being able to perform the process accurately.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a sectional view showing another embodiment of the present invention. 2... Force motor, 2b... Output end (drive shaft), 4... Piston, 5, 6... Fluid introduction chamber, 11
... Pivotal support member, 12 ... Feedback rod, 12
c... Middle part, 16... Fluid control mechanism.

Claims (1)

[Claims] 1. A force motor that converts an input electrical signal into a small displacement amount of an output end that can move back and forth in the axial direction,
An output piston whose axis is positioned parallel to the axis of this force motor and which is arranged between a pair of fluid introduction chambers and moves forward and backward in the axial direction according to the pressure difference between the two fluid introduction chambers, and this piston. and a pivot member held so that it can be screwed back and forth in a direction perpendicular to the axis of the force motor; an extendable feedback rod facing the output end of the force motor;
A fluid control mechanism that selectively supplies pressurized fluid to either one of the fluid introduction chambers by comparing the displacement amount of the intermediate portion of the feedback rod with the displacement amount of the output end opposite to this displacement amount. An electrical/mechanical conversion device characterized in that the piston outputs an operating amount proportional to the input to the force motor.