JPH0643706Y2 - Load test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a load testing device used for load testing of rotating machines such as reduction gears. More specifically, generation of a braking torque applied to a test rotating machine is described. The present invention relates to a load test device using a hydraulically actuated brake as a means.

[Conventional technology]

A load test device using a hydraulically actuated brake as a braking torque generating means is disclosed, for example, in Japanese Utility Model Application No. 62-46342.
It is disclosed in Japanese Patent Publication No. The brake is a so-called wet multi-plate brake, which includes a housing that is supported in a fixed state and a shaft body that is rotatably supported inside the housing, and the rotation is restricted outside the shaft body so that the brake is coaxial. Of a plurality of brake plates that are mounted on the housing and a plurality of brake plates that are mounted on the inside of the housing in the same manner are alternately polymerized through the oil enclosed in the housing. Braking torque is generated by the shear resistance of the oil film between the braking plates. A load test apparatus using this brake supports the housing so as to be swingable within a predetermined angle range via a swing arm having a predetermined length that projects radially outward from the housing. Inside this housing, an operating cylinder that is operated by hydraulic pressure and presses the braking plate on the shaft side in the axial direction is provided on the housing side, and at the bearing position of the swing arm by the force applied via the arm. A hydraulic control valve for controlling the hydraulic pressure supplied to the working cylinder by the movement of the valve body and a load cell for detecting the acting force at this time are provided, and the rotary shaft of the rotating machine under test is linked to the shaft body. At the same time, the hydraulic control valve is used in a state in which an oil pressure corresponding to the torque to be tested is applied to the valve body of the hydraulic control valve in a direction opposite to the force applied to the valve body via the swing arm. At this time, the working cylinder is advanced by the working oil fed via the hydraulic control valve, whereby the load torque of the rotating machine under test is transmitted to the housing via the braking plates pressed against each other. As a result of acting on the valve body of the hydraulic control valve via the swing arm, the valve body balances at a position where this force and the hydraulic pressure are equal, and the braking torque generated by the brake is close to the set torque. Equilibrate at. As a result, the brake repeats the braking operation associated with the pressing of the braking plate and the braking release operation associated with the release of the pressing before and after the set torque to obtain the load torque of the test rotating machine near the set torque. To be The force acting on the valve element via the swing arm is detected by the load cell, and the detection result is used as a feedback signal when the set torque is changed.

Now, in such a load test apparatus, the set torque is changed at any time in order to simulate various loads, but in order to obtain the transient characteristics of the rotating machine under test at the time of changing the load, the brake is generated. The braking torque needs to respond to the change of the set torque at a high speed. The applicant of the present application is
A load test that can follow the change of the set torque at high speed by making the working cylinder of a double-acting type and forcibly moving the piston of the working cylinder not only to the braking side but also to the releasing side. The device was proposed in Japanese Utility Model Application No. 63-100060. FIG. 5 is a schematic diagram showing the configuration of the hydraulic circuit of this load test apparatus.

Reference numeral 2 in the drawing includes a rotary shaft 1 that is interlocked with a rotary shaft A of the test rotating machine, and a housing 3 that rotatably accommodates the rotary shaft 1. These hydraulically operated brakes are arranged alternately. Housing 3
A double-acting working cylinder 10 is formed inside the cylinder, and when hydraulic oil is supplied to one of the oil chambers 10a of the cylinder 10, the piston 100 advances to move the braking plates to each other. When pressed, the brake 2 generates a braking torque,
When hydraulic oil is supplied to the other oil chamber 10b, the piston 100
By pushing in and out, the pressing state between the brake plates is released,
The brake 2 releases the braking torque. An oscillating arm 4 is provided on the outside of the housing 3, and the oscillating arm 4 is supported via a valve body 5 of a hydraulic control valve 6 fixed in a vertical position. A load cell 18 for detecting a force acting on the valve body 5 via the arm 4 is provided between the valve body 5 and the swing arm 4.

The valve body 5 is in the shape of a cylinder having two large diameter portions at the top and bottom, and inside the hydraulic control valve 6, a first oil chamber below the lower large diameter portion and a second oil between both large diameter portions. 3rd upper part of chamber and upper large diameter part
It forms an oil chamber. The hydraulic oil of the working cylinder 10 generated by the hydraulic pump 9 is passed through the accumulator to the second oil.
The control hydraulic pressure supplied to the pump port 10 ′ communicating with the oil chamber and generated by the hydraulic pump 50 is passed through the current control type pressure control valve 12 to the hydraulic action ports 8 of the first and third oil chambers.
Supplied to A and 8B. 39A, 39B are these hydraulic action ports 8A,
It is a control port on the pressure control valve 12 side that is connected to 8B. Also,
A return spring 7 for urging the valve body 5 toward the center is provided in the first and third oil chambers.
A and 7B are arranged. Further, the hydraulic control valve 6 is provided with brake ports 11R and 11F, and when the hydraulic pressures in the oil chambers 8A and 8B are balanced, these brake ports 11F and 11R are connected by the large diameter parts of the valve body 5. Although it is blocked, if the balance of hydraulic pressure in the oil chambers 8A and 8B is broken and the piston moves to the first oil chamber (or third oil chamber) side, the brake port near the first oil chamber (or third oil chamber) 11R (or 11F) opens into the second oil chamber, and the working oil of the working cylinder 10 supplied to the oil chamber is 4
It is supplied to the oil chamber 10a or 10b of the working cylinder 10 through the solenoid switching valve 16 of the port 3 position switching type. The electromagnetic switching valve 16 is for automatically switching the flow path of the working oil according to the forward and reverse directions of the rotating shaft 1.

In the load test apparatus as described above, when a signal corresponding to the test torque is applied to the pressure control valve 12, a predetermined hydraulic pressure is supplied to, for example, the hydraulic action port 8A, the valve element 5 moves upward, and the brake port 11F opens in the second oil chamber. Further, the electromagnetic switching valve 16 is switched to one side which is determined according to the rotation direction of the rotating shaft A of the test rotating machine, and the hydraulic pressure in the second oil chamber passes through the brake port 11F and the oil chamber of the working cylinder 10. Supplied to 10a. As a result, the piston 100 of the working cylinder 10 advances and the brake 2 operates, and the braking torque in the rotation direction is applied to the housing 3. This braking torque is applied to the valve body 5 via the swing arm 4,
I'm going to move this downward. The valve body 5 is pressed upward by the hydraulic pressure corresponding to the set torque equivalent force, and equilibrates when the upward pressing force and the downward swinging force become equal. When the braking torque transmitted from the swing arm 4, that is, the braking torque generated by the brake 2 fluctuates, the valve body 5 slightly moves, which opens the brake port 11R or 11F, and the hydraulic pressure generated by the hydraulic pump 9 changes. , Oil chamber 10b or 10a of working cylinder 10
The brake force of the brake 2 is changed by this, and the valve body 5 returns to the equilibrium position. The hydraulic pressure supplied to the oil chambers 10a, 10b is proportional to the opening of the brake ports 11F, 11R determined by the displacement of the valve body 5, as shown in FIG. As shown in FIG. 5, P _{0 in} FIG. 6 is the source pressure of the oil supplied to the working cylinder 10, and P is the piston.
100 working oil pressure.

On the other hand, when the set torque is changed, the hydraulic pressure supplied to the hydraulic action port 8A changes, so the valve body 5 moves according to the unbalanced amount, and the accompanying brake port 11R or 11F causes the oil chamber 10a of the working cylinder 10 or Brake 2 with pressure oil supplied to 10b
The braking operation or the releasing operation is performed, and the braking torque generated by the brake 2 changes following the set torque. That is, in this load testing device, the working cylinder 10 is a double-acting type, and the hydraulic pressure is supplied to the oil chamber 10a or 10b to both brake and release the brake 2, so that the set torque is set. It is possible to quickly follow any changes in the, and it is possible to perform a transient load test of the rotating machine under test.

[Problems to be solved by the device]

Now, in the load test apparatus shown in FIG. 5, one of the oil chambers 10a of the working cylinder 10 is changed by changing the set torque as described above.
When hydraulic oil is supplied to the piston 10
By advancing 0, the hydraulic oil remaining in the other oil chamber 10b is eliminated. At this time, since the brake port 11R communicating with the oil chamber 10b is closed by the valve body 5, the hydraulic oil is removed by using the return oil passage 10d communicating the oil chamber 10b with the oil tank T. This recirculation oil passage 1
In order to maintain the pressure of the hydraulic oil in a stable state at the time of braking, 0d is provided with a fixed throttle having a minute opening which makes a pair with the variable orifice. As a result of being hindered by the throttle, there is a drawback in that the effect of making the working cylinder 10 of the double-acting type in order to enhance the responsiveness when the set torque is changed is not sufficiently exhibited.

The present invention has been made in view of such circumstances, and realizes prompt removal of hydraulic oil from the oil chamber of the working cylinder,
It is an object of the present invention to provide a load testing device with further improved transient characteristics when changing the set torque.

[Means for Solving the Problems]

The load testing apparatus according to the present invention is a hydraulically operated brake in which a shaft that rotates in conjunction with a test rotating machine is housed in a housing that is swingably supported, and a brake for braking the brake.
A double-acting working cylinder for moving each piston in the releasing direction is provided, while a hydraulic pressure for feeding to the working cylinder is formed by the movement of the valve body according to the swinging force acting on the supporting portion of the housing. Is a load test apparatus comprising a hydraulic control valve for controlling, wherein the hydraulic control valve is such that when one oil chamber of the working cylinder communicates with a source of working hydraulic pressure, the other oil chamber serves as a low pressure source. It is characterized by being opened.

[Action]

In the present invention, one oil chamber of the double-acting working cylinder is communicated with the hydraulic power source through the hydraulic control valve, and when the working oil is fed, the other oil chamber is passed through the hydraulic control valve. The hydraulic oil remaining in the oil chamber is released to the low pressure source at an opening proportional to the communication opening, and is quickly removed to the low pressure source via the hydraulic control valve to brake the brake. The torque changes immediately following this.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof.

FIG. 1 is a schematic diagram showing the configuration of a hydraulic circuit of a load testing apparatus according to the present invention, FIG. 2 is a longitudinal sectional view showing the internal structure of a hydraulically actuated brake used as a braking force applying means, and FIG. It is a principal part enlarged view of FIG.

The configuration of the load test apparatus according to the present invention is basically the same as the configuration of the conventional load test apparatus shown in FIG. 5, and a hydraulically operated brake 2 that generates a braking torque to be applied to the test rotating machine, In order to perform the braking and releasing operations of the brake 2, a hydraulic pressure control valve 6 configured to control the hydraulic pressure supplied to the working cylinder 10, a hydraulic pump 9 for generating the working hydraulic pressure of the working cylinder 10, A hydraulic pump 50 for generating a control hydraulic pressure of the hydraulic control valve 6, and a current control type pressure control valve 12 interposed between the hydraulic pump 50 and the hydraulic control valve 6 for controlling the distribution of the control hydraulic pressure are provided. The load test apparatus according to the present invention is characterized by the structure of the hydraulic control valve 6.

First, the structure of the brake 2 will be briefly described. The brake 2 is a rotary shaft 1 that is linked to the rotary shaft A of the test rotating machine.
And a housing 3 that rotatably supports the rotary shaft 1 and has oil sealed inside, and the rotary shaft 1 is rotated between a number of braking plates mounted on both of them while restraining their rotation. Accompanying
It is a wet multi-plate brake that generates a braking force by the shear resistance of an oil film. FIG. 2 is a longitudinal sectional view showing the upper half portion in a braking state and the lower half portion in a released state. The rotary shaft 1 is inserted into the housing 3 from the left side in the figure for an appropriate length, and the rotary shaft A side,
That is, the left side is supported by the bearings 27A and 27B, and the tip portion, that is, the right end portion in the drawing is supported by the bearing 27C. In addition, the housing 3 is provided with the rotating shaft 1 between the bearings 30, 30 standing upright on the left and right sides, and separate bearings 28 are provided.
It is rotatably supported via A and 28B. Inside the housing 3, there is provided a surrounding cylinder 91 surrounding the outside of the rotary shaft 1. Inside the surrounding cylinder 91, rotation is restricted by the surrounding cylinder 91 and a large number of movable cylinders in the axial direction are provided. A brake plate is attached. Further, also in the portion surrounded by the surrounding cylinder 91 on the outer side of the rotary shaft 1, rotation is restricted by the rotary shaft 1, and a large number of braking plates are attached so as to be movable in the axial direction. The both brake plates are alternately superposed in the axial direction. At the right end of housing 3, bearing 28C
The rotary joint 92 is rotatably fitted through the
Oil introduced and introduced through the rotary joint 92 and an oil passage 94 connected to the rotary joint 92 is enclosed in 91. This oilway
The left end portion of 94 is formed at the center of the rotary shaft 1 and is connected to the oil passage 1a which is connected to the positions where the bearings 27A and 27B are arranged. The oil introduced through the oil passage 94 is the bearings 27A and 27B.
It is also used as a lubricating oil for the high pressure oil seal 7D.

The brake 2 generates a braking torque by moving the braking plates close to each other in the surrounding cylinder 91, and releases the braking torque by moving the braking plates away from each other, and the braking torque is released on the right side of the surrounding cylinder 91. An operating cylinder 10 for pressing a brake plate to perform the approach is constructed. This working cylinder 10 is of the double-acting type proposed in the above-mentioned Japanese Patent Application No. 63-100060, and has two oil chambers 10a and 10b,
When hydraulic oil is supplied to one of the oil chambers 10a, the piston 100 moves forward to press the braking plate closer, and when hydraulic oil is supplied to the other oil chamber 10b, the piston 100 is On the contrary, it is designed to move in and out. Further, as shown in FIG. 3, a separating operation due to the withdrawal of the piston 100 is quickly generated between the braking plates,
Return springs 103, 103… that urge these mutually in the separating direction.
Are installed respectively.

The working cylinder 10 has a stepped ring-shaped piston 100 fitted in a stepped ring hole (a large diameter on the braking plate side and a small diameter on the side farther from the stepped plate) formed around the right end portion of the surrounding cylinder 91. In the oil chamber 10a formed on the right side of the large diameter portion of the stepped annular hole, the oil passage 93 formed on the right side surface of the housing 3 is provided.
The hydraulic oil is introduced via a and into the oil chamber 10b formed on the left side of the small diameter portion via an oil passage 93b similarly formed.

On the outside of the housing 3 of the brake 2, a swing arm 4 of a predetermined length is provided so as to project. The swing arm 4 is a valve body of a hydraulic control valve 6 which is a feature of the present invention and which is fixed in a vertical position. 5, a load cell 18 for detecting a braking torque-equivalent load applied to the valve body 5 via the arm 4 is provided at a connecting portion between the valve body 5 and the swing arm 4.

Now, FIG. 1 shows a detailed vertical cross-sectional view of the hydraulic control valve 6, and as shown in this figure, the hydraulic control valve 6 is provided at four locations arranged in parallel in the axial direction at predetermined intervals. A first oil chamber 61 formed on the lower side of the lowermost large diameter portion, and a second valve formed between the large diameter portions in order from the lower side.
An oil chamber 62, a third oil chamber 63, a fourth oil chamber 64, and a fifth oil chamber 65 formed on the uppermost side of the large diameter portion are provided. The oil supplied to the working cylinder 10 generated by the hydraulic pump 9 is constantly connected to the third oil chamber 63 in the pump port 63.
a through an accumulator, and also
The control pressure oil generated by the hydraulic pump 50 is
Through the separate control ports 39A and 39B of the pressure control valve 12, they are respectively supplied to a control port 61a which is always connected to the first oil chamber 61 and a control port 65a which is also always connected to the fifth oil chamber 65. . Further, the second oil chamber 62 and the fourth oil chamber 64 are opened to the oil tank T maintained at a low pressure state via respective separate return ports 62a, 64a which are always connected to these. The first oil chamber 61 located at the bottom and the fifth oil chamber 65 located at the top
Return springs 7A and 7B for urging the valve body 5 toward the center are provided therein, and when there is no pressure difference between the oil chambers 61 and 65, the valve body 5 returns the return springs 7A and 7B. A spring center is formed at a position (neutral position) determined by the urging force of the springs 7A and 7B, and then stopped.

Now, in the hydraulic control valve 6, when the valve body 5 is in the neutral position, the hydraulic control valve 6 is closed at the large-diameter portions on both sides of the third oil chamber 63.
A pair of brake ports 11R and 11F are opened. First
If the hydraulic equilibrium state between the oil chamber 61 and the fifth oil chamber 65 is broken and the valve body 5 moves downward (or upward), the brake port 11R (or 11F) located on the lower side (or upper side) Open into the third oil pressure 63, and the working oil supplied into the oil chamber 63 passes through a 4-port 3-position switching type electromagnetic switching valve 16 to pass through the oil chamber 10a or 10b of one of the working cylinders 10. At this time, the other brake port 11F (or 11R) is opened in the fourth oil chamber 64 (or the second oil chamber 62) and the return port 64 is opened.
The oil chamber T is opened to the oil tank T via a (or the return port 62a), and the other oil chamber 10b or 10a of the working cylinder 10 directly communicates with the oil tank T via the electromagnetic switching valve 16 and the hydraulic control valve 6. To be done. The electromagnetic switching valve 16 is provided in order to prevent the brake lock from occurring by switching the flow path of the hydraulic oil according to the forward / reverse direction of rotation of the rotary shaft 1.

The device of the present invention as described above sets a required torque equivalent voltage in a torque setting device (not shown), and applies this to a servo amplifier (not shown) to output a corresponding signal, which is applied to the pressure control valve 12 and electromagnetic switching. The valve 16 is used in a state of being switched according to the rotating direction of the test rotating machine. Accordingly, the control hydraulic pressure generated by the hydraulic pump 50 is controlled by the control port 61a connected to the first oil chamber 61 and the control port 6 connected to the fifth oil chamber 65.
5a and 5a, respectively, for example, the first oil chamber 61 to the fifth oil chamber
In the direction toward 65, a pressure difference corresponding to the set torque is generated, and as the valve body 5 moves upward due to this pressure difference, as described above, the brake port 11F enters the third oil chamber 63. Also, the brake port 11R has the second oil chamber 62.
Open inside each. Therefore, the hydraulic oil supplied into the third oil chamber 63 via the pump port 63a is not controlled by the electromagnetic switching valve 16
And is sent to the oil chamber 10a on the advancing side of the working cylinder 10,
Along with this, the hydraulic oil staying in the retreat side oil chamber 10b quickly flows back to the oil tank T through the electromagnetic switching valve 16 and the second oil chamber 62 of the hydraulic control valve 6, and the piston 100 quickly When the brake plates are pressed against each other, the braking resistance is generated by the brake 2 due to the shear resistance of the oil film between the brake plates, and the housing 3 is not rotated in the rotation direction of the rotary shaft 1. This braking torque is applied to the valve body 5 via the swing arm 4, and the valve body 5 is pressed downward by this applied force, so that the first oil chamber 61 and the fifth oil chamber 65 are separated from each other. It stops at a position where the pressure difference and the braking torque applied via the swing arm 4 are in equilibrium. When the braking torque generated by the brake 2 fluctuates, the valve body 5 also moves up and down accordingly, which causes the brake port 11R or 11F to move into the third oil chamber 63, and the brake port 11F or 11R to move to the third position. 4 oil chamber 64
Alternatively, as a result of opening each in the second oil chamber 62, the working cylinder 10
The piston 100 moves slightly, the braking torque of the brake 2 changes, and the valve body 5 returns to the equilibrium state. Such a valve body 5
Also occurs when the set torque is changed, and in this case as well, the braking torque of the brake 2 changes due to the same operation, and the valve element 5 is in the equilibrium state at the time when this changes to the changed set torque. Return to.

As described above, in the load test apparatus according to the present invention, the movement of the valve body 5 causes one of the brake ports 11R and 11F to move to the third position.
Since it opens in the oil chamber 63, and the other opens both in the second oil chamber 62 or the fourth oil chamber 64 opened to the oil tank T,
At the same time as the hydraulic oil is fed to one of the oil chambers 10a and 10b of the working cylinder 10, the hydraulic oil staying in the other is promptly discharged to the oil tank T, and the movement of the valve body 5 and the movement of the piston 100 occur. During this period, high responsiveness is obtained, and the braking and releasing of the brake 2 accompanying the movement of the piston 100 rapidly follow the movement of the valve body 5 that occurs according to the change of the set torque.

FIG. 4 shows the braking that is actually generated by the brake 2 when the set torque is changed stepwise in the load testing apparatus according to the present invention and the conventional load testing apparatus shown in FIG. 6 is a graph showing a comparison of changes in torque over time. In the conventional load test apparatus shown on the upper side of the figure, the braking torque generated by the brake 2 largely fluctuates after the set torque is changed, and it takes a long time to converge to a new set torque equivalent value. On the other hand, in the load test apparatus according to the present invention shown on the lower side, both the fluctuation range and the number of fluctuations of the braking torque after the change of the set torque are small, and the braking torque quickly converges to a new set torque equivalent value. Thus, in the load testing machine according to the present invention,
The responsiveness at the time of changing the set torque is greatly improved, and it is possible to quickly follow frequent changes in the set torque.

[Effect of device]

As described above in detail, in the load test apparatus according to the present invention, the hydraulic control valve for controlling the hydraulic pressure fed to the double-acting working cylinder that moves each piston in the direction of braking and releasing the brake has the above-mentioned operation. When one of the oil chambers of the cylinder communicates with the generation source of the working oil pressure, the other oil chamber is opened to the low pressure source, so that the movement of the piston due to the feeding of the working oil to the one oil chamber causes The present invention exerts an excellent effect such that braking and releasing are quickly performed without being hindered by the hydraulic oil remaining in the oil chamber, and responsiveness at the time of changing the set torque is significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of a hydraulic circuit in a load test apparatus according to the present invention, FIG. 2 is a vertical cross-sectional view of a hydraulically actuated brake which is means for generating braking torque, and FIG. FIG. 4 is an enlarged view of a part, FIG. 4 is a graph showing a state of improvement of responsiveness by the load testing device according to the present invention, FIG. 5 is a schematic diagram showing a configuration of a hydraulic circuit in a conventional load testing device, and FIG. 6 is a hydraulic control. 5 is a graph showing a change state of hydraulic pressure supplied to both oil chambers of an operating cylinder with respect to displacement of a valve body of a valve. 1 ... Rotary shaft, 2 ... Brake, 3 ... Housing, 4 ... Swing arm, 5 ... Valve body, 6 ... Hydraulic control valve, 10 ... Working cylinder, 10a, 10b ... Oil chamber, 100 ... Piston, T ... Oil tank

Claims (1)

[Scope of utility model registration request] 1. A hydraulically actuated brake in which a shaft body that rotates in conjunction with a rotating machine under test is housed in a housing that is swingably supported, and a piston in the direction of braking and releasing the brake. A hydraulic control valve which is provided with a double-acting actuating cylinder for each movement, and which is configured in the bearing portion of the housing and controls the hydraulic pressure supplied to the actuating cylinder by the movement of the valve body according to the acting swinging force. A load testing apparatus comprising: the hydraulic control valve configured to open the other oil chamber to a low pressure source when the one oil chamber of the working cylinder communicates with a generation source of the working hydraulic pressure. A load test device characterized by the above.