JPH0743253A - Load test equipment - Google Patents

Abstract

PURPOSE:To deal with the transient characteristic test of a sample rotating machine for particular form of load, e.g. an engine for vessel, by allowing the test under a load torque which follows up the variation of rotational speed in peculiar mode. CONSTITUTION:The load test equipment comprises a hydraulic brake, a hydraulic pressure regulating means, a servo amplifier for controlling the pressure regulating means, a unit 60 disposed on the input side of a transmission element 8 for converting a torque command signal Es into a brake torque Tb in order to perform the power operation of a rotational speed signal En obtained through detection of the rotation speed of a sample rotating machine coupled with the output side of the transmission element 8 and positive feeding back the output to the servo amplifier thus determining the load characteristics under a load torque following up the rotational speed, wherein an output from an arbitrary function generator 61 is superposed on an output signal from the unit 60 to produce an output signal following up the rotational speed in special mode which can not be represented by the unit 60 and the test is conducted similarly for that output signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load testing apparatus used for load testing of rotating machines. More specifically, a hydraulically actuated brake is used as a means for generating a load torque applied to a test rotating machine. Load test apparatus.

[0002]

2. Description of the Related Art A load testing apparatus using a hydraulically actuated brake as a load torque generating means is disclosed, for example, in Japanese Utility Model Application Laid-Open No. 2-21538 and Japanese Patent Application Laid-Open No. 3-56837. The brake is a so-called wet multi-plate brake, which is provided with a housing and a rotation shaft rotatably supported inside the housing, and has a large number of coaxially mounted rotation-restricted outsides of the rotation shaft. Of the rotary braking plate, and a large number of fixed braking plates similarly mounted inside the housing,
Alternately polymerized through the oil enclosed in the housing,
It is configured such that these are pressed against each other by an operating cylinder operated by hydraulic pressure to generate a braking torque.

In the load test by the load testing device, the housing of the brake constructed as described above is supported via a swing arm of a predetermined length which is provided on the outer side of the brake housing, and the rotary shaft is also tested. The load applied to the support portion of the swing arm (load equivalent to the braking torque) by the reaction of the braking torque generated by the brake is detected by the interlocking connection with the machine, and the feedback signal of the detection result and the torque command given from the outside are detected. The brake hydraulic pressure supplied to the working cylinder is regulated based on the signal to adjust the braking torque generated by pressing the working cylinder, and the desired load torque corresponding to the torque command signal is supplied to the working cylinder. It is performed with a load on the trial rotating machine.

The load testing devices disclosed in Japanese Utility Model Laid-Open No. 2-21538 and Japanese Patent Laid-Open No. 3-56837 are interposed in the supporting portion of the swing arm to apply the braking torque equivalent load in one direction. A hydraulic control valve having a spool, and a current control type pressure control valve for generating a control hydraulic pressure for urging the spool in the opposite direction are provided, and a configuration for adjusting the brake hydraulic pressure by these is provided. Has become. The feedback signal of the load equivalent to the braking torque is given to the servo amplifier which performs the control operation of the pressure control valve together with the torque command signal, and the servo amplifier gives a deviation between the two signals, that is,
An operation of controlling the operating current of the pressure control valve is performed in order to eliminate the deviation between the braking torque actually generated by the brake and the target torque.

That is, the spool of the hydraulic control valve has a load equivalent to the braking torque acting from one side through the swing arm and a pressing load acting on the other end surface by the control hydraulic pressure sent from the pressure control valve. Maintaining a balanced position, the brake will generate a braking torque corresponding to the torque command signal. Further, in this state, when the braking torque generated by the brake changes due to various disturbances, the spool is displaced in the acting direction of the braking torque equivalent load,
At this time, the control operation of the servo amplifier according to the deviation generated between the feedback signal of the braking torque and the torque command signal increases or decreases the control oil pressure sent from the pressure control valve. , The brake is quickly returned to the equilibrium position before the displacement, and the brake constantly continues to generate the braking torque.

On the other hand, when the torque command signal is changed, the control oil pressure is increased or decreased so as to eliminate the deviation between the changed torque command signal and the current braking torque. When the brake is displaced to the equilibrium position, the brake generates a braking torque corresponding to the changed torque command signal and loads the test rotating machine. in this way,
By appropriately changing the torque command signal, the load test under constant torque of the test rotating machine is performed.

Further, the load test apparatus disclosed in the above-mentioned Japanese Patent Laid-Open No. 3-56837 is mainly used for the load test under the constant torque described above, and is carried out in a state where the rotation speed of the rotating machine under test is kept constant. Actual use of the rotating machine under test, such as constant speed test, constant power test performed with the absorbed power by the brake kept constant, and speed following torque test under load torque that changes following changes in rotation speed. The load test can be performed by simulating various load states at various times.

Among these, the speed following torque test is provided with a rotation speed detector for detecting the rotation speed of the test rotating machine, is given a detection signal of the rotation speed detector, and follows a change in this detection signal. This is realized by a structure in which a speed following signal generating section for outputting a changing signal is provided, and the output signal of the speed following signal generating section is sequentially added to the torque command signal and given to the servo amplifier.

The speed following signal generator outputs a signal that follows proportionally to the n-th power of rotation speed (1≤n≤3). When the speed following torque test is selected, In the servo amplifier, the control operation described above is performed on the input to which the output of the speed following signal generator is added, and the load characteristics of the test rotating machine under the torque that changes following the rotational speed are Obtained continuously.

[0010]

The speed following torque test as described above is extremely useful for knowing the transient characteristics from the start up to the steady operation, and in many rotating machines under test. The load torque after starting increases in proportion to the rotation speed or the power of the rotation speed and reaches the steady operation, so that the desired characteristics can be obtained by the configuration described above.

However, depending on the type of the rotating machine under test,
There are some cases where the increase in the load torque before reaching the steady operation does not follow the increase process described above. For example, in a marine engine for driving a propulsion screw of a ship, at the time of start-up, the ship is in a substantially stopped state, but after start-up, since the ship itself advances as the screw rotates, The relative relationship between the screw and the water agitated by this is different immediately after startup and before steady operation.
Therefore, the load torque of the marine engine rapidly increases with an increase in the rotation speed immediately after starting, but the degree of this increase becomes gentle as the marine vessel progresses and changes by following the process shown in FIG.

The transient characteristic of the marine engine that follows such a changing process cannot be obtained by the conventional speed following torque test carried out as described above. In the conventional load test apparatus, the marine engine or the like is used. However, there was a problem that it was not possible to deal with the transient characteristic test of the test rotating machine used in a special load mode.

The present invention has been made in view of such circumstances, and enables a test under a load torque that follows and changes in a peculiar manner with respect to a change in rotation speed, and can be used for a marine engine, etc.
It is an object of the present invention to provide a load test device capable of coping with a transient characteristic test of a test rotating machine having a special load form.

[0014]

A load test apparatus according to the present invention comprises a hydraulically actuated brake which is interlocked with a rotating machine under test, means for adjusting a brake hydraulic pressure supplied to the brake, and the brake. A servo amplifier that controls the pressure adjusting means based on a feedback signal of a braking torque generated by the motor and a torque command signal given from the outside, and a speed that outputs a signal that changes following the change in the rotation speed of the test rotating machine. A follow-up signal generator is provided, and the output of the speed follow-up signal generator is added to the torque command signal so that the load test of the rotating machine under test can be performed under a load torque that changes following the change in rotation speed. In the load test apparatus described above, a correction signal is attached to the speed following signal generating section, and a correction signal is generated according to a function that is appropriately set therein, and the output of the speed following signal generating section is corrected. Characterized by including the arbitrary function generator.

[0015]

In the present invention, the output signal of the speed following signal generator which changes in proportion to the rotational speed or the power of the rotational speed is increased or decreased by the correction signal output from the arbitrary function generator according to the rotational speed. A signal that has a special form and changes according to the change in rotation speed is obtained, and this signal is added to the torque command signal and given to the servo amplifier to control the braking torque applied to the test rotating machine.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a schematic diagram showing the configuration of a hydraulic circuit of a load test apparatus according to the present invention. As shown in the figure, the load test apparatus is a hydraulically operated brake 1 that generates a load torque, and braking and release of the brake 1. to occupy perform the operation, the hydraulic control valve 2 for controlling the feed oil pressure to the actuation cylinder 10 arrangement (the brake pressure P _b) in the interior of this, the hydraulic pump 30 is a source of brake fluid pressure P _b, the hydraulic control A hydraulic pump 31 that is a source of a control hydraulic pressure P _c that is added to the spool 20 of the valve 2 as described below, and is interposed between the hydraulic pump 31 and the hydraulic control valve 2 to distribute the control hydraulic pressure P _c . And a current control type pressure control valve 32 for controlling

The brake 1 supports a rotating shaft 11 which is interlocked with the output shaft of the test rotating machine A, and supports the rotating shaft 11.
A wet multi-disc brake including a housing (12) in which oil is enclosed, and a braking torque is generated by a shear resistance of an oil film between a large number of braking discs attached to both of them while restraining their rotation. 2 is a vertical cross-sectional view showing the internal structure of the brake 1, and FIG. 3 is an enlarged view of a main part of FIG. The upper half of FIG. 2 shows the braking state, and the lower half of FIG. 2 and FIG. 3 show the braking released state.

The housing 12 of the brake 1 is swingably supported via a pair of bearings 12A and 12B between a pair of bearings C and C, which are vertically erected on a base (not shown) with a proper distance. Has been done. The rotating shaft 11 of the brake 1 is a housing
12 is inserted from one side (the left side in the figure), and the insertion side, that is, the middle part of the left side is fitted and fixed to the housing 12 by the bearings 11A and 11B. Each of them is supported by a bearing 11C that is fitted and fixed, and can rotate about its axis.

The housing 12 is provided with an inner housing 14 which surrounds the outer side of the rotary shaft 11.
A large number of braking plates are attached to the inner circumference of the so as to be restrained from rotating and movable in the axial direction. In addition, in the surrounding portion of the inner housing 14 on the outer periphery of the rotating shaft 11,
Rotation is restricted by the rotary shaft 11, and a large number of braking plates are attached so as to be movable in the axial direction.
The braking plates on the inner circumference of the inner housing 14 are alternately superposed in the axial direction.

At the right end of the housing 12, the bearing
A rotary joint 15 is fitted through 15A, and the rotary joint 15 and an oil passage continuous with the rotary joint 15 are provided inside the inner housing 14.
Oil introduced and discharged via 16 is enclosed. The left end of this oil passage 16 is an oil passage that penetrates the center of the rotating shaft 11.
16a, the bearings 11A and 11B are communicated with the positions where the bearings 11A and 11B are arranged. Has become.

When the braking plates on the rotating shaft 11 side and the inner housing 14 side are brought close to each other, the brake 1 applies a braking torque by the shear resistance of the oil film generated between the two through the enclosed oil inside the inner housing 14. When they are generated and are separated from each other, the braking torque is released.
On the right side of the inner housing 14, a double-acting working cylinder 10 for pressing a brake plate to perform the approach is formed. The working cylinder 10 is provided with two oil chambers 10a and 10b, and a piston 100 that receives internal pressures of these oil chambers on both sides thereof.

As shown in FIG. 3, the working cylinder 10 is provided with a stepped ring hole (a large diameter on the braking plate side and a small diameter on the far side) on the right end portion of the inner housing 14,
A corresponding stepped annular piston 100 is fitted. The oil chamber 10a on one side of the piston 100 is formed on the right side of the large diameter portion of the stepped annular hole, and the oil chamber 10b on the other side is formed on the left side of the small diameter portion, and separate oil passages 17a and 17b are formed. Through the right outer wall of the housing 12 at different positions, and these oil chambers 10a and 10b are connected to the open ends of the oil passages 17a and 17b through separate pipe joints 19a and 19b, respectively. Oil pipe
The brake oil pressure _Pb is introduced through 18a and 18b.

Thus, the piston 100 has one oil chamber 1
Advanced operative to press the brake plate when the brake hydraulic pressure P _b is introduced into 0a, brake hydraulic pressure P to the other oil chamber 10b
_{When b} is introduced, it will move in and out. Disc springs 101, 101, ... for urging the brake plates against each other in a separating direction are interposed between the brake plates, and when the piston 100 retracts, each brake plate has a disc spring between them. 101,1
It is separated by the spring force of 01 ..., and the braking is reliably released.

At the center of the housing 12 of the brake 1 constructed as described above, a swing arm 13 (see FIG. 1) of a predetermined length is provided so as to project outward in the radial direction. The front end of the hydraulic pressure control valve 2 is supported by the spool 20 of the hydraulic control valve 2 which is vertically fixed on the base. spool
A load cell 41 for detecting the equivalent load of the braking torque applied to the spool 20 via the swing arm 13 in association with the generation of the braking torque by the brake 1 is provided at the connecting portion between the 20 and the swing arm 13. ing.

The hydraulic control valve 2 as shown in detail in FIG.
It has a built-in cylindrical spool 20 having four large-diameter portions arranged at predetermined intervals in the axial direction, and forms a first oil chamber below the lowermost large-diameter portion. Second, third, and fourth oil chambers are formed between the large diameter portions in order from the bottom, and further a fifth oil chamber is formed above the uppermost large diameter portion. Hydraulic braking pressure P _b of the hydraulic pump 30 is generated is supplied to the third fluid chamber via the pump port 23, also hydraulic said hydraulic pump 31 is generated, a control port 32A and the hydraulic control valve of the pressure control valve 32 2
Is supplied to the first oil chamber via the control port 21 of the control port 32 of the pressure control valve 32 and the control port of the hydraulic control valve 2
It is supplied to the fifth oil chamber via 25. Also, the hydraulic control valve 2
The second oil chamber and the fourth oil chamber are opened to an oil tank T maintained at a low pressure via separate return ports 22 and 24.

Return springs 2A and 2B for urging the spool 20 toward the center are arranged in the first oil chamber located at the bottom and the fifth oil chamber located at the top, respectively. There is no pressure difference in the control oil pressure P _c supplied to the oil chamber via the pressure control valve 32, and the swing arm 13 is provided in order to prevent the swing of the housing 12 caused by the reaction of the braking operation of the brake 1. If there is no external force (braking torque equivalent load) acting via the spring, the spool 20 forms a spring center at a position (neutral position) determined by the spring load of the return springs 2A and 2B and stops. It has become.

When the spool 20 is in the neutral position, the hydraulic control valve 2 has openings at positions closed by the large diameter portions on both sides of the third oil chamber, and has a pair of brake ports 26R, 2R.
6F is formed. Thus, spool from the neutral position
When 20 moves downward (or upward), the brake port 26R (or 26F) located on the lower side (or upper side) is the third
The brake oil pressure P _b supplied to the third oil chamber via the pump port 23 is 4 ports 3
It is fed to one of the oil chambers 10a and 10b of the working cylinder 10 through the position switching type electromagnetic switching valve 33 and the separate oil feeding pipes 18a and 18b, and the brake 1 performs braking or braking releasing operation.

On the other hand, at this time, the other brake port 26F (or 26R) of the hydraulic control valve 2 opens in the fourth oil chamber (or the second oil chamber), and the return port 24 (or the return port 22) is used. Open to the oil tank T. Therefore, the hydraulic oil discharged from the other oil chamber 10b, 10a by the above-described operation of the brake 1 returns to the oil tank T via the respective oil feed pipes 18b, 18a, the electromagnetic switching valve 33 and the hydraulic control valve 2, Without damaging the operation of the piston 100 for braking or releasing braking, the braking and releasing operations occur at high speeds. Also, the hydraulic control valve 2
The electromagnetic switching valve 33 between the brake 1 and the brake 1 switches the feed path of the brake oil pressure P _b according to the forward / reverse rotation direction of the rotary shaft 11 connected to the output shaft of the test rotary machine A. It is provided to prevent the occurrence of brake lock.

The spool of the hydraulic control valve 2 is constructed as described above.
When acting on 20 via the swinging arm 13 corresponding to the braking torque corresponding to the braking operation of the brake 1, the return spring 2
The spring load of A and 2B and the first and the fifth through the pressure control valve 32.
Control load F _c corresponding to control oil pressure P _c introduced into the oil chamber
(Refer to FIG. 4) The brake 1 moves in the vertical direction according to the balance with the force, and the brake 1 performs a braking operation or a brake releasing operation by the brake oil pressure P _b supplied according to the movement of the spool 20.

A speed detector 42 is interposed between the cylinder block of the hydraulic control valve 2 and the spool 20. The speed detector 42 is a linear speed converter that generates a speed signal corresponding to the moving speed of the spool 20, and the detection result of the speed detector 42 is the detection result of the load equivalent to the braking torque of the brake 1 by the load cell 41. It is also used as a feedback signal for damping correction of the target torque.

Further, as shown in FIG. 2, a rotation speed detector 43 is fixed on the support base C located on the protruding side of the rotary shaft 11 in the brake 1, and the rotary shaft 11 is projected through the timing belt 44. Connected to the department. As the rotation speed detector 43, the rotating shaft 11 and the test rotating machine A that rotates together with the rotating shaft 11 are used.
A rotary encoder that emits a predetermined number of pulse signals per revolution is used. This pulse signal is converted into a voltage signal corresponding to the rotation speed of the test rotating machine A as described later, and constant speed and constant power control is performed. Is used as a feedback signal for changing the torque command signal.

In the load test by the load test apparatus having the above-mentioned structure, the output shaft of the test rotating machine A is connected to the rotary shaft 11 of the brake 1.
After the preparatory work for changing the switching position of the electromagnetic switching valve 33 according to the rotation direction of the test rotating machine, a control signal corresponding to a desired target torque is given to the drive circuit of the pressure control valve 32. This is performed by changing the operating current to the pressure control valve 32. As a result, the hydraulic pressure generated by the hydraulic pump 31 is introduced into the first and fifth oil chambers of the hydraulic control valve 2 as the control hydraulic pressure P _c having a distribution ratio determined by the operation of the pressure control valve 32. Then, a pressure difference corresponding to the target torque occurs.

For example, when the pressure difference of the control oil pressure P _c is generated from the first oil chamber to the fifth oil chamber and the electromagnetic switching valve 33 is switched to the lower position, the spool 20 changes to the control oil pressure P _c . By the action of the corresponding control load F _c , the return spring 2B moves upward from the neutral position against the biasing force, and the brake port 26F opens in the third oil chamber and the brake port 26R opens in the second oil chamber. To do. As a result, from the hydraulic pump 30 to the third
Hydraulic braking pressure P _b supplied to the oil chamber, the brake port
The oil is fed to the advancing side oil chamber 10a of the working cylinder 10 through the 26F, the electromagnetic switching valve 33 and the oil feeding pipe 18a, while the retreating side oil chamber 1
The hydraulic oil inside 0b is returned to the second oil chamber through the oil feed pipe 18b, the electromagnetic switching valve 33 and the brake port 26R, and is discharged to the oil tank T. As a result, the working piston 100 rapidly advances, the braking plates on the rotating shaft 11 side and the inner housing 14 side are pressed against each other, and the brake 1 generates braking torque due to the shear resistance of the oil film between the braking plates. It is assumed that the housing 12 is not rotated in the rotation direction of the rotating shaft 11.

At this time, the braking torque generated by the brake 1 is converted into a load equivalent to the braking torque via the swing arm 13 and applied to the spool 20.
Is a balance between the braking torque equivalent load acting downward, the control load F _c acting upward due to the control oil pressure P _c introduced into the first and fifth oil chambers, and the spring loads of the return springs 2A and 2B. Stop in position. In this state, when the braking torque generated by the brake 1 fluctuates due to disturbance, the spool 20 of the hydraulic control valve 2 also moves up and down, which changes the opening mode of the brake ports 26R, 26F and the piston 100 of the working cylinder 10 moves. As a result of the inching, the braking torque generated by the brake 1 automatically returns to the torque before the change, that is, the target torque.

Such movement of the spool 20 occurs even when the setting of the target torque is changed and the control oil pressure P _c introduced into the first and fifth oil chambers of the oil pressure control valve 2 is changed,
In this case as well, the same operation changes the braking torque of the brake 1, and at the time when this changes to the changed target torque, the spool 20 reaches a new equilibrium position and the brake 1
Generate a braking torque corresponding to the equilibrium position, that is, a braking torque corresponding to the newly set target torque.

The operation of the load test apparatus according to the present invention has been described above by paying attention to the oil flow, but in this apparatus, the load equivalent to the braking torque generated by the brake 1 is caused by the load cell 41, and this load fluctuates. The moving speed of the spool 20 of the hydraulic control valve 2 added via the arm 13 is detected by the speed detector 42, respectively, and the feedback control based on the detection result is performed. Further, the rotation speed of the test rotating machine A that rotates while being applied with the braking torque by the brake 1 is detected by the rotation speed detector 43, and using this detection signal, the load torque that changes following the change of the rotation speed. The following test (speed following torque test) is performed.

FIG. 4 is a block diagram of a control system of the load testing apparatus according to the present invention. In the constant torque control which is a basic control function, the target torque is given to the servo amplifier 5 as a voltage signal (torque command signal E _s ) corresponding to this magnitude.

The servo amplifier 5 also has a torque feedback signal E _b detected by the load cell 41 and corresponding to the braking torque equivalent load, and a speed feedback signal E _b detected by the speed detector 42 and corresponding to the moving speed of the spool 20. ₀ is given, and the servo amplifier 5 determines the control amount of the pressure control valve 32 based on these signals,
An operation of outputting a control signal to the pressure control valve 32 is performed.

The specific operation of the pressure control valve 32 is performed according to the control signal electrically given from the servo amplifier 5.
The throttle opening corresponding to each of the pair of control ports 32A, 32B is changed. When this change is made, a difference occurs in the control hydraulic pressure P _c on the downstream side of both control ports 32A, 32B.
This control oil pressure P _c acts on the spool 20 of the oil pressure control valve 2. That is, the control signal output from the servo amplifier 5 includes the pressure control valve 32 and the hydraulic piping system connected to the pressure control valve 32, and as shown in FIG. 4, passes through the charge-weight conversion unit 34 represented as a proportional element having _a proportional sensitivity K _a. Converted to the dimension of force, control load F
It becomes _c and acts on the spool 20.

The hydraulic control valve 2 is replaced by a mechanical addition point 27, an inertial delay element 28 and a pressure conversion section 29. The mechanical addition point 27 corresponds to the spool 20. At the mechanical addition point 27, the control load F _c , which is the output of the charge-to-charge converter 34, the spring load F ₀ of the return springs 2A and 2B, and the brake. The braking torque equivalent load F _b added from the first housing 12 via the swing arm 13 is added. On the spool 20, the displacement x corresponding to the force balance of each load, which is the output of the mechanical addition point 27, is
20 via the inertial delay element 28 which corresponds to the resistance during movement, the displacement x including the hydraulic hose from the hydraulic control valve 2 to the brake 1 and the pressure with a first-order lag transfer function with gain K _p. It is converted into a brake oil pressure P _b in the converter 29 and is sent to the brake 1.

The gain K _p of the pressure converting unit 29 is a pressure gradient coefficient showing the rate of change of the brake oil pressure P _b with respect to the displacement x of the spool 20, and the rate of change with time of the displacement x of the spool 20 generated as described above. The (moving speed) is detected by the speed detector 42 and is fed back to the servo amplifier 5 as a speed feedback signal E ₀ .

The brake 1 for generating the braking torque T _b in response to the supply of the brake oil pressure P _b regulated by the hydraulic pressure control valve 2 has a hydraulic pressure addition point 35 and a torque conversion portion as shown in the figure.
Replaced with 36. The hydraulic pressure addition point 35 is the brake 1
This is equivalent to the working cylinder 10 of
In the above, the brake hydraulic pressure P _b supplied from the hydraulic control valve 2 and the biasing force of the return springs 101, 101 ...
The equivalent piston return pressure P _r obtained by dividing by the pressure receiving area at 10a is added to the piston 100 of the working cylinder 10.
Presses the brake plate by the force multiplied by the difference between the two pressures (P _b -P _r) to the pressure receiving area.

This pressing force passes through the torque conversion unit 36 represented as a proportional element having a proportional sensitivity K _c and the braking torque T.
converted to _b . The proportional sensitivity K _c of the torque converter 36
Is the braking torque T _{b with} respect to the pressing force of the piston 100.
Is a brake constant indicating the rate of change of the brake plate. This brake constant K _C is the effective diameter D _{m of the} brake plates and the number Z, the dynamic friction coefficient μ between the brake plates, the pressure receiving area A of the piston 100, and other dimensions of each part of the brake 1. And a constant that depends on the viscosity of the oil enclosed in the housing 12. T _b = K _c (P _b −P _r ) ∵K _c = μZD _m A

The braking torque T _b thus generated is the braking torque equivalent load F _b divided by the length L of the swing arm 13.
Is added to the spool 20 of the hydraulic control valve 2, that is, the mechanical addition point 27. Also, this braking torque equivalent load F
_b is a load cell 41 mounted on the supporting portion of the swing arm 13.
The detection result is sent to the servo amplifier 5 as a torque feedback signal E _b corresponding to the braking torque equivalent load F _b via the feedback amplifier 37. The feedback amplifier 37 is a fixed amplifier that amplifies the output of the load cell 41 in order to obtain the torque feedback signal E _b having a level corresponding to the torque command signal E _s .

[0045] The internal configuration of the servo amplifier 5 is shown in Japanese Patent Application No. 5-115811 filed by the present applicant, although a detailed description is omitted, the servo amplifier 5, a torque command signal E _s and the torque The proportional calculation value using the deviation from the feedback signal E _b is used as the torque feedback signal E
The control amount of the pressure control valve 32 is determined by the PD operation for reducing the amount of correction by the differential value of _b , and for improving the response, the control amount is increased by the feedforward signal obtained by the differentiation of the torque command signal E _s. Corrections are being made. Further, the servo amplifier 5 outputs a control signal in which the deviation between the corrected control amount and the speed feedback signal E ₀ is given a first-order advance by the series advance compensation circuit configured on the output side, and the pressure control is performed. The first-order delay component held by the pressure conversion unit 29 including the valve 32 and the hydraulic piping system is offset.

In the load testing apparatus according to the present invention having the basic control system as described above, the speed follow-up signal generating operation for changing the torque command signal E _{s according} to the change in the rotation speed of the test rotating machine A is generated. The section 6 is arranged in parallel with the servo amplifier 5 so that a speed following load test can be performed in order to know the transient characteristics and the like after the startup of the test rotating machine A. Figure 5
FIG. 3 is a block diagram showing a configuration of a control system including a velocity tracking signal generator 6. In addition, in this figure, in order to prevent the drawing from being complicated, the entire basic control system shown in FIG.
It is shown in lieu of a transfer element 8 with _b / E _s ).

The braking torque T which is the output of the transmission element 8
_b is a test rotary machine A connected to the rotary shaft 11 of the brake 1.
Be transmitted to. As shown in FIG. 5, the test rotating machine A can be replaced with a mechanical addition point 80 and an inertia element 81,
The braking torque T _b generated by the brake 1 is applied to the test rotating machine A at the mechanical addition point 80, and the rotation speed of the test rotating machine A is the driving torque T _{0 of} itself and the braking torque T _b of the brake 1. The difference is determined by adding to the inertial element 81 containing the load inertia J ₀ of the rotating part.

The rotation speed of the test rotating machine A is detected by the rotation speed detector 43 connected to the rotation shaft 11 of the brake 1. This rotation speed detector 43 is, as shown, 30 / π
By multiplication of the unit conversion constant 44 with proportional sensitivity
The rotation speed of the test rotating machine A having a speed dimension of N (rpm) is converted into a rotation signal having the number of pulses per unit time corresponding to this, and the rotation signal is detected. The output signal of the device 43 is converted into a voltage signal (rotational speed signal E _n ) by the F / V converter 82 having a conversion constant K _n, and is supplied to the speed following signal generator 6 which is a feature of the present invention.

The speed following signal generator 6 is connected to the power calculator 60, the input changeover switch SW ₄ , the arbitrary function generator 61, the selection switch SW ₃ and the polarity converter 62 in series with the input side of the servo amplifier 5. Cut-off switch SW ₀ and adder mounted
65, and the output of the polarity converter 62 is applied to the input side of the adder 65 via the changeover switch SW ₁ . The selection switch SW ₃ has three selection positions (n ₁ , n ₂ , n
It is a switch that has ₃ ) and can be switched from the outside. The input changeover switch SW ₄ is provided with two switching positions (n _2, n _3), is the automatic switch without such automatic switching is performed according to switching to the corresponding selection position of the selection switch SW ₃ . That is, the input changeover switch SW ₄ is subordinate to the selection switch SW ₃ .

The rotation speed signal E _n is given to one switching position n ₃ of the input changeover switch SW ₄ and the power calculator 60. The power calculator 60 receives the rotation speed signal E which is an input signal.
_The output signal corresponds to _{n to} the n-th power (1 ≦ n ≦ 3), and this output signal is applied to the other switching position n _{2 of the} input switching switch SW ₄ and the selection switch S.
It is given to the selected position n _{1 of} W ₃ .

An arbitrary function generator 61, which is a feature of the present invention, is provided between the input changeover switch SW ₄ and the selection switch SW _3.
Is installed. This is a well-known control device that can set an arbitrary function inside and outputs an output obtained on the function set for an input. This arbitrary function generator 61 has an input changeover switch. Different inputs are given according to the switching position of SW ₄ .
That is, when the switching position of the input selector switch SW ₄ is n ₂ , the output of the power calculator 60 ( _n of the rotation speed signal E _n is
When the switching position is n ₃ , the rotation speed signal E _n is given as it is.

The input changeover switch SW ₄ is changed over in accordance with the operation of the selection switch SW ₃ , as described above. Accordingly, the polarity converter 63 connected to the output side of the selection switch SW ₃ is different signal is provided in response to the operation position of the selection switch SW _3. First, when the selection position of the selection switch SW ₃ is n ₁ , the output of the power calculator 60, that is, the signal corresponding to the n-th power of the rotation speed signal E _n is given to the polarity converter 63, and the selection position is also changed. When n is ₂ , the polarity converter 63 is provided with a signal in which the output of the arbitrary function generator 61 is superimposed on the nth power of the rotation speed signal E _n , and when the selected position is n ₃ , the polarity is changed. The input to the converter 63 is
The arbitrary function generator 61 is added to the rotation speed signal E _n itself (first power).
The output of is a superimposed signal.

The polarity converter 63 performs the operation of converting the sign according to the rotation direction of the rotating machine under test A and applying a predetermined amplification, and each input given to the polarity converter 63 as described above is
A signal having a level and a sign corresponding to the torque command signal E _s is taken out, and this output signal is given to the adder 65 when the changeover switch SW ₁ is turned on.

The constant torque control, which is a basic control function, is
This is performed by turning off the changeover switch SW ₁ and turning on the cutoff switch SW ₀ . At this time, in the adder 65 on the input side of the servo amplifier 5, the torque command signal E _s is given through the cutoff switch SW ₀ , while the input from the speed following signal generation unit 6 is cut off, and as a result, the servo amplifier 5 is cut off. An externally set torque command signal E _s is directly applied to the brake amplifier 5, and the brake 1 operates in accordance with the above-described operation of the servo amplifier 5 to cause the brake torque T _b corresponding to the torque command signal E _s. Is continuously generated, and the braking torque T
Load characteristics under _b are required.

On the other hand, the load test under the load torque which changes following the change of the rotation speed, that is, the speed following torque test,
Turn on the changeover switch SW ₁ to turn off the cutoff switch SW
It is performed by turning off ₀ . At this time, in the adder 65, the torque command signal E is turned off by turning off the cutoff switch SW _{0.
When s} is cut off and the changeover switch SW ₁ is turned on, the output of the speed following signal generating unit 6 is given, and the servo amplifier 5 performs a control operation according to the output of the speed following signal generating unit 6.

The output of the speed following signal generator 6 is proportional to the power of the rotation speed signal E _n corresponding to the rotation speed of the test rotating machine A, and is output to the servo amplifier 5 after the changeover switch SW ₁ is changed over. Torque command signal E given
_s is a signal that changes in accordance with the power of the change in the rotation speed (including the first power). As a result of the servo amplifier 5 performing a control operation for this input, the test rotating machine A changes in accordance with the change in the rotation speed. The load torque to be applied is continuously applied, and the speed following torque test of the rotating machine under test A, which is important for knowing the transient characteristics after starting, is performed.

Here, the selection switch SW ₃ is at the selection position n.
_{When it is 2} or n ₃ , the output of the speed following signal generator 6 is the power of the rotation speed signal E _n , or the rotation speed signal E _n.
The output of the arbitrary function generator 61 is superimposed on itself. The arbitrary function generator 61, since may set an appropriate function from the outside, it can be made a signal that randomly follow the output signal of the speed tracking signal generating section 6 to a change in the rotational speed signal E _n. For example, a function as shown in FIG. 6A is set in the arbitrary function generator 61, and as shown in FIG.
When the square output of the rotation speed signal E _n is set to, and when the selection switch SW _{3 is set} to the selection position n ₂ , the output signal of the speed following signal generator 6 is (a) in FIG. )
6 (c) obtained by synthesizing (b) and (b) corresponds to the change mode (see FIG. 7) of the load torque necessary to know the transient characteristic of the marine engine.

As described above, in the load testing apparatus according to the present invention in which the speed tracking signal generating section 6 is provided with the arbitrary function generator 61, the change of the rotation speed of the test rotating machine A is randomly followed. It is possible to perform load tests by applying load torque,
As in the case of the marine engine described above, it becomes possible to obtain the transient characteristics in a form close to the actual usage state of various test rotating machines A.

[0059]

As described in detail above, in the load testing apparatus according to the present invention, the output of the speed following signal generator which regularly changes in accordance with the rotation speed or the change of the rotation speed is corrected by the output of the arbitrary function generator. However, since this signal is given to the servo amplifier to perform the control operation, it is possible to realize a load state in which the rotating machine under test changes irregularly by following changes in the rotation speed, and various transient characteristics of the rotating machine under test are The present invention has excellent effects such that the present invention can be implemented in a form close to each actual use state.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a hydraulic circuit of a load test apparatus according to the present invention.

FIG. 2 is a vertical cross-sectional view of a hydraulically actuated brake that is a means for generating load torque.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a block diagram showing a basic configuration of a control system of the load test apparatus according to the present invention.

FIG. 5 is a block diagram showing a configuration of a control system including a velocity tracking signal generator, which is a feature of the present invention.

FIG. 6 is an explanatory diagram of a mode of forming an output signal of a speed following signal generation unit.

FIG. 7 is a diagram showing how the load changes when the marine engine starts to sail.

[Explanation of symbols]

1 Brake 2 Hydraulic control valve 5 Servo amplifier 6 Speed following signal generator 10 Working cylinder 10a Oil chamber 10b Oil chamber 11 Rotating shaft 12 Housing 13 Swing arm 32 Pressure control valve 41 Load cell 42 Speed detector 43 Rotation speed detector 60 Should be adder 61 arbitrary function generator 64 analog memory 82 F / V converter 100 piston A test試回turning point E _s torque command signal E _b torque feedback signal E _n rotational speed signal

Claims (1)

[Claims] 1. A hydraulically actuated brake, which is interlocked with a rotating machine under test, pressure adjusting means for brake hydraulic pressure supplied to the brake, and a feedback signal of a braking torque generated by the brake, which is provided from the outside. A servo amplifier that controls the pressure adjusting means based on a torque command signal, and a speed following signal generator that outputs a signal that changes according to changes in the rotation speed of the test rotating machine are provided. In addition to the torque command signal the output of the section, the load test apparatus, which is capable of performing a load test of the test rotating machine under a load torque that changes following a change in rotation speed,
It is characterized by further comprising an arbitrary function generator which is attached to the speed following signal generating section, which emits a correction signal according to a function appropriately set therein, and corrects an output of the speed following signal generating section. Load test equipment.