JPH07253382A - Testing apparatus of characteristic of clutch friction plate - Google Patents

Abstract

PURPOSE:To obtain the testing apparatus in which the rotational speed on the output side of a clutch in a sliding coupling state can be maintained constant with high accuracy at the initial stage of a test, whose test accuracy is enhanced by making an initial condition and a boundary condition constant when a succeeding coupling operation is strengthened and which can obtain a test result of high reliability. CONSTITUTION:A shaft torque Tc which is taken out at an output shaft 13 via a clutch C and a transmission 12 is detected by a torque detector 15, and the rotational speed No of the output shaft 13 is detected by a rotational-speed detector 17. In addition, a rotational speed Ni on the input side to the clutch C from an engine 10 is detected by a rotational-speed detector 16. In addition, the coupling operating force of the clutch C is detected, as a clutch oil pressure Pc given to the clutch C, by an operating-force detector 28 installed additionally at a pressure-regulating valve 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can grasp the frictional behavior of friction plates during actual operation in a clutch that engages or disengages input from a rotary drive source such as an engine or a motor by pressing or releasing the friction plates. Device for a characteristic test to be carried out.

[0002]

2. Description of the Related Art In a power transmission system for transmitting the output of a rotary drive source to an appropriate output end, for example, a traveling transmission system of a tractor, a main clutch and a transmission for transmitting the output of an engine as a rotary drive source to a transmission. Many clutches that engage and disengage the input from the rotary drive source are used, such as a speed change clutch for realizing a speed change by switching the power transmission path inside, and these clutches include a transmission side and a transmission side. In addition, a friction clutch configured to generate an engagement torque by pressing friction plates whose rotations are restricted to each other is widely used.

Friction clutches include a hydraulic clutch and a pneumatic clutch depending on the difference in friction environment between the dry type clutch and the wet type clutch, and the construction of the operating means for generating the pressing force between the friction plates, that is, the engaging operation force. , Spring force clutches, etc., and these types are selected according to usage conditions such as required magnitude of engagement torque, degree of engagement / disengagement frequency, and surrounding environment. On the other hand, in the proper selection of the friction clutch, it is important to accurately grasp the characteristics of the friction plate including the durability. Therefore, the transmission system including the friction clutch, such as the transmission system for traveling of the tractor, is important. In the above, a characteristic test for investigating the characteristics of the friction plate of the clutch under actual operation has been conventionally performed.

In this test, the transmission system from the engine through the main clutch to the transmission is fixed on a bench test stand, and the output shaft of the transmission, which is the output end, is
By connecting to the test load via an inertial body that simulates inertia during actual operation, in the past, first, the clutch to be tested was slip-engaged while applying a predetermined load by the test load, and the rotation speed on the output side Is maintained at a predetermined value (determined with reference to the rotational speed input from the engine), the load is released, and the engagement operation force of the clutch is increased to accelerate the inertial body. The procedure for measuring the time to reach the input rotation speed (engagement completion time) is repeated, and the actual operating load in the actual vehicle is repeatedly reproduced on the bench test bench.

[0005]

In the characteristic test conducted as described above, the durability of the friction plate is evaluated by the increase of the engagement completion time with time, and the output rotation until the engagement is completed. The characteristics of the friction plate are evaluated by observing the changing state of the speed. To make these assessments accurate,
The rotational speed on the output side under the above-mentioned sliding engagement state is kept constant near the center value of the predetermined value, and the acceleration of the inertial body by the subsequent strengthening of the engagement of the clutch is performed starting from the same state. It is important to let them do it.

Conventionally, in order to maintain the speed in a slipping state, a means for adjusting the engaging operation force of the clutch (in the case of a hydraulically operated clutch, a pressure adjusting valve for adjusting the operating oil pressure) is provided. While being connected to a position control means capable of accurate position control, the rotation speed of the output side of the clutch is detected, and the position control means is operated according to the fluctuation of the detection result to adjust the clutch engagement operation force. The constant speed state is obtained by the procedure.

However, since the conventional procedure as described above is an open loop method, a certain degree of fluctuation component remains in the rotational speed on the output side in the sliding engagement state, and it is substantially maintained. It is impossible, and the acceleration of the inertial body due to the strengthening of the engagement of the subsequent clutch is performed under different conditions for each repetition. As a result, the engagement completion time obtained as described above and the output rotation speed during that period are obtained. There is an inconvenience that it is not possible to compare the increasing states in the same row. Therefore, in order to obtain a predetermined test result, the test personnel are required to have skill, and it is possible to avoid individual differences in the evaluation of the characteristics of the friction plate even when the test personnel have sufficient skill. However, the reliability of the test results obtained is low, and it is necessary to set a sufficient safety factor in the design of the friction plate based on such test results, and the miniaturization of the transmission system is realized. Has become a factor that inhibits.

The present invention has been made in view of the above circumstances, and it is possible to maintain the initial condition of the rotational speed on the clutch output side at a high accuracy in a slip engagement state, and the boundary condition for subsequent engagement strengthening. It is an object of the present invention to provide a characteristic test device for a clutch friction plate, which can improve the test accuracy by making the above constant and obtain reliable test results without requiring skill.

Further, the characteristic values required for the evaluation of the clutch friction plate are quantitatively calculated during the test, and the objective characteristic evaluation based on the calculation result can be accurately performed. An object of the present invention is to provide a device for testing the characteristics of a clutch friction plate that can contribute to the achievement of miniaturization of a transmission system including a clutch.

[0010]

According to a first aspect of the present invention, there is provided a clutch friction plate characteristic testing device, wherein an output side of a clutch for engaging and disengaging an input from a rotary drive source is connected to a test load via an inertial body. Then, after obtaining a sliding engagement state between the friction plates of the clutch under a predetermined load condition by the test load, the load is released and the engagement operation force of the clutch is increased to accelerate the inertial body. Then, the engagement completion time until reaching the input rotational speed from the rotary drive source is measured, and in the characteristic device of the clutch friction plate for performing the characteristic evaluation including the durability of the friction plate based on the result, Means for adjusting the engagement operation force of the clutch, a rotation speed detector for detecting the rotation speed on the output side of the clutch, and a detection result corresponding to the detection result. Rotation speed fee The rotational speed command signal is corrected based on back signal, characterized by comprising a servo amplifier for outputting an operation control signal of the adjusting means.

Further, the servo amplifier is a PID in which a PI calculator that receives a deviation between the rotation speed command signal and the rotation speed feedback signal is provided in parallel with a differentiator that receives the rotation speed feedback signal. A proportional portion having a difference between the feedback signal corresponding to the displacement of the adjusting means or the shaft torque on the output side of the clutch and the output of the PID calculating portion as an input. A differentiator, which receives the displacement or torque feedback signal as an input, is provided in parallel with the computing unit P
It is characterized by including a D operation unit.

On the other hand, according to a second aspect of the present invention, there is provided a clutch friction plate characteristic testing device in which an output side of a clutch for engaging and disengaging an input from a rotary drive source is connected to a test load via an inertial body.
After obtaining a sliding engagement state between the friction plates of the clutch under a predetermined load condition by the test load, the load is released and the engagement operation force of the clutch is increased to accelerate the inertial body, In the clutch friction plate characteristic test device for measuring the engagement completion time until reaching the input rotation speed from the rotary drive source, and performing the characteristic evaluation including the durability of the friction plate based on the result, A rotational speed detector that detects the rotational speed of each of the input side and the output side, an operating force detector that detects the engaging operating force of the clutch, and a torque detector that detects the axial torque on the output side of the clutch, It is characterized by further comprising: a characteristic calculation unit that calculates a characteristic value related to the frictional behavior of the friction plate using the respective detection results and sequentially outputs the characteristic value.

Further, the characteristic calculating section includes means for calculating a friction power per unit area of the friction plate, and means for detecting a zero crossing time point of the output of the means.
The device for testing the characteristics of a clutch friction plate according to claim 5, further comprising means for specifying a time required until completion of the engagement based on the detection result.

[0014]

In the first aspect of the invention, in order to obtain the target rotational speed that is appropriately set on the output side of the clutch to be tested,
The detection result of the rotation speed obtained at the output side of the clutch as a result of this control is fed back to the servo amplifier which issues a control signal to the adjusting means for adjusting the engaging force of the clutch, and the rotation speed command signal is supplied by this feedback signal. Is corrected to automatically adjust the engagement operation force of the clutch so that the rotation speed on the output side in the slip engagement state is kept constant. At this time, the result of the PI calculation using the deviation between the rotation speed command signal and the rotation speed feedback signal is corrected by the differential value of the rotation speed feedback signal to determine the control amount of the adjusting means. Keep the rotation speed constant with higher precision.

In addition, the displacement of the adjusting means or the axial torque on the output side of the clutch is detected, and a feedback signal corresponding to the detection result of either one of them and the control amount (output of the PID computing section). The deviation of the adjusting means is corrected by the differential value of the feedback signal to obtain the operation control signal to be output to the adjusting means, whereby the delay of the adjusting means is absorbed and corrected, and the rotation speed on the output side is corrected. Can be kept constant with even higher precision.

In the second aspect of the invention, the rotational speeds of the input side and the output side of the clutch to be tested, the axial torque of the output side, and the engaging force of the clutch are detected and given to the characteristic calculating section. , The characteristic values related to the friction behavior of the friction plates, specifically, the friction power and the total friction work per unit area of the friction plates, the dynamic friction coefficient between the friction plates, etc. are calculated and sequentially output. By referring to the results, it is possible to eliminate the need for skill in characteristic evaluation of the friction plate, eliminate the occurrence of individual differences, and perform error-free characteristic evaluation. Further, the zero crossing time point of the friction power calculated by the characteristic calculation unit is detected, and the result is used to correctly specify the time required for completion of the engagement, thereby realizing the durability evaluation with high accuracy.

[0017]

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 view showing a usage state of a clutch friction plate characteristic test device according to the present invention (hereinafter referred to as the device of the present invention). As shown in the figure, in the test by the device of the present invention, the assembly of the test transmission system 1 including the engine 10 serving as the rotary drive source, the main clutch 11, and the transmission 12 is fixed on the bench test bench and protrudes to the outside of the transmission 12. It is implemented by connecting the output shaft 13 to the test load B via the torque detector 15 and the inertial disk 14.

The inertial disk 14 simulates an inertial element that is rotationally driven by the output shaft 13 in the actual operating state of the test transmission system 1. For example, the test transmission system 1 is a traveling transmission system for a tractor. , The outer diameter and thickness of the inertial disk 14 are
It is set to have an inertia element that makes an inertial motion with the rotation of the output shaft 13, mainly an inertia corresponding to the weight of the wheel and chassis. Further, the test load B may be any one that can apply a predetermined load torque to its own input shaft used for connection with the output shaft 13, and various types such as wet or dry multi-plate brakes and powder brakes. A brake or dynamometer can be used.

FIG. 2 is a model diagram showing the configuration of the device of the present invention. The device of the present invention is for performing a characteristic test of the friction plate of the main clutch 11 or the transmission clutch built in the transmission 12. C in FIG. 2 indicates a test clutch, and the rotational force of the engine 10 is transmitted to the transmission 12 (gear ratio i) via the clutch C and the output shaft 13
And the load torque T _b generated by the test load B
It acts to rotate the inertial disk 14 having an inertia of J against.

The output shaft torque T _c of the clutch C is detected by the torque detector 15 interposed between the output shaft 13 and the inertial disk 14. As the torque detector 15, for example, a torsion bar having a small diameter and a strain gauge attached to the torsion bar are provided, and the twist generated in the torsion bar due to the action of the axial torque T _c is applied to the output voltage of the bridge circuit including the strain gauge. With a configuration in which it is taken out as a change of, or a torsion bar and a pair of gears attached to both sides of this,
A voltage output corresponding to the axial torque T _c can be obtained, such as a configuration in which the twist generated in the torsion bar due to the action of the axial torque T _c is taken out through the deviation amount of the tooth flanks of both gears detected by each separate pickup. Various available torque detectors can be used.

Further, the rotational speed detector 16, 17 and the output shaft 13 and the engine 10 is Yes and respectively attached, the former rotational speed N _i of the input side of the clutch C is detected by, and the output of the clutch C by the latter rotational speed N _o emerging through the transmission 12 to the side is detected. These rotation speed detectors 16 and 17 output a plurality of pulse signals per one rotation of the engine 10 and the output shaft 13, and the input rotation speed N _i and the output rotation speed N _o are the pulse signals of the respective pulse signals. It is used as a signal obtained by converting the frequency into a voltage by a conversion means such as an F / V converter.

The clutch C to be tested is provided with adjusting means 2 for variably adjusting the engaging operation force of the clutch C. When the clutch C is a hydraulically operated clutch, the adjusting means 2 may be any one that operates a pressure adjusting valve 18 (see FIG. 2) that is arranged in the vicinity of the clutch C and adjusts the operating oil pressure. Various actuators that perform a linear operation with respect to various control signals can be used.

FIG. 3 shows an example of the adjusting means 2. The adjusting means 2 includes a current control type hydraulic servo valve 20 and a hydraulic cylinder 21 that operates by the hydraulic pressure fed from the servo valve 20.
The output rod 22 of the hydraulic cylinder 21 is connected to the operating end of the pressure regulating valve 18 projecting outside of the clutch C via an appropriate connecting means such as a push-pull wire to displace the output rod 22. With x, the pressure regulating valve 18 is modeled by the mass m, the spring constant k, and the damping constant η to operate the pressure regulating valve 18. The displacement x is detected by a displacement detector 23 provided in parallel with the hydraulic cylinder 21, and is used for controlling the servo valve 20 as described later. The displacement detector 23 is for converting the displacement of the detection rod 24 connected to the output rod 22 into a voltage signal, and is configured by using a potentiometer, a differential transformer and the like.

In the characteristic test of the clutch C by the device of the present invention constructed as described above, the clutch C is slip-engaged with the test load B set to the predetermined load torque T _b as in the conventional case, and the clutch C is engaged. After a predetermined rotation speed is obtained on the output side of C, the load torque T _b of the test load B is released, the engaging force of the clutch C is increased, and the inertial disk 14 connected via the output shaft 13 is accelerated. It is done by procedure. In the present invention apparatus during this time, the output speed N _o by the rotational speed detector 17 arranged on the output side of the clutch C is similarly by the torque detector 15 shaft torque T _c of the output side of the clutch C is,
Further, the displacement x of the adjusting means 2 is detected by the displacement detector 23, and the operation control of the adjusting means 2 based on these detection results, specifically, the operating current of the hydraulic servo valve 20 controls the clutch C. The degree of engagement is adjusted so that the output rotation speed N _o is kept constant in the slipping state.

FIG. 4 is a block diagram showing the overall configuration of the control system of the device of the present invention. The servo amplifier 3 for controlling the operating current of the hydraulic servo valve 20 is supplied with a voltage signal (rotational speed command signal E _s ) corresponding to the target rotational speed of the clutch C. The servo amplifier 3 also has a displacement detector.
A voltage signal (displacement feedback signal _Ex ) corresponding to the displacement x of the adjusting means 2 detected by 23 or a torque detector
Output side shaft torque T _c of clutch C detected by 15
Corresponding voltage signal (torque feedback signal E _T )
Are provided in accordance with the changeover of the changeover switch 7. Further, the servo amplifier 3 includes a rotation speed detector.
A voltage signal (rotational speed feedback signal E _N ) corresponding to the output rotational speed N _o of the clutch C detected by 17 is provided, and the servo amplifier 3 processes each of these signals as described below, and the hydraulic servo valve The control signal is issued to 20.

The hydraulic servo valve 20 controls the hydraulic pressure fed to the hydraulic cylinder 21 by the movement of the built-in spool generated according to a control signal electrically supplied from the servo amplifier 3, and has an electric power having a proportional constant K _0. It is represented as an oil conversion part. Further, the hydraulic cylinder 21 operated by this feed hydraulic pressure is represented as a transfer element having a secondary delay transfer function including a mass m as a load, a spring constant k and a damping constant η. The symbol A included in the transfer function of the hydraulic cylinder 21 is the pressure receiving area of the working piston inside the hydraulic cylinder 21.

That is, the control signal output from the servo amplifier 3 is converted into the displacement x by the adjusting means 2 including the hydraulic servo valve 20 and the hydraulic cylinder 21. This displacement x is converted into a displacement feedback signal E _x multiplied by a predetermined conversion constant H ₀ via the displacement detector 23 and fed back to the servo amplifier 3 and, as described above, the clutch C.
It is added to the operation end of the pressure regulating valve 18 connected to.
The pressure regulating valve 18 operates to regulate the clutch hydraulic pressure P _c for engaging the clutch C according to the displacement of the built-in spool, and is represented as a displacement-hydraulic pressure conversion unit having a pressure gradient coefficient K _V. It

The clutch C is, as schematically shown in FIG.
This is a multi-plate clutch that presses a plurality of friction plates, which are arranged to face each other at appropriate intervals, by an operating piston that receives the clutch hydraulic pressure P _c , and generates an engagement torque by a frictional force generated between them. The pressing by the working piston is performed against the spring force of a return spring (not shown) interposed between the friction plates. That is, in the clutch C, the equivalent piston return pressure P _r obtained by dividing the spring load of the return spring by the pressure receiving area of the working piston is used as the clutch hydraulic pressure P _c.
Oil pressure addition point 26 to be subtracted from and transmission 12
Proportional element having a transfer function iK _c including the gear ratio i of
27, and the clutch hydraulic pressure P _c is converted into the axial torque T _c of the output shaft 13 via the hydraulic pressure addition point 26 and the proportional element 27.

The engaging operating force of the clutch C is calculated by the operating force detector.
28 (see FIG. 2). The operating force detector 28 is specifically a pressure detector attached to the oil supply pipe from the pressure regulating valve 18 in order to detect the clutch oil pressure P _c sent to the clutch C. The result is given to the characteristic calculation unit 5 described later as a voltage signal (engagement operation force signal E _p ) corresponding to the engagement operation force of the clutch C. The characteristic calculation unit 5 is supplied with the rotation speed feedback signal E _N and the torque feedback signal E _T obtained respectively as described above, and further,
A voltage signal (input rotation speed signal E _i ) corresponding to the input rotation speed N _i of the clutch C detected by the rotation speed detector 16 mounted on the 10 is also provided.

The shaft torque T _c taken out to the output shaft 13 is
A decreased load torque T _b by test load B in the mechanical summing point 29, both the difference (T _c -T _b) inertia disc
Is added to 14, the rotational speed N _o of the output shaft 13 is determined. The shaft torque T _c is converted into a voltage signal by the torque detector 15 and is multiplied by a predetermined gain by the amplifier 8 to become a torque feedback signal E _T , which is fed back to the servo amplifier 3 and to the characteristic calculation section 5. Has been given.

The inertial disk 14 is represented as an integral element including its inertia J. Output rotational speed N _o detected by the rotation speed detector 17 are those in rpm multiplied by 30 / [pi to the output (with a dimension of the angular velocity) of the transmission element corresponding to the inertia disc 14, the detection The result is the conversion constant H
It converted by F / V converter 9 having ₂ to a voltage signal, while being fed back to the servo amplifier 3 as a rotational speed feedback signal E _N, is given to the characteristic calculating unit 5. Similarly, the input rotation speed N _i detected by the rotation speed detector 16 is F / V having the conversion constant H _1.
The converter 6 converts the input rotation speed signal E _i , which is a voltage signal, to the characteristic calculation unit 5.

FIG. 5 is a block diagram showing the internal structure of the servo amplifier 3. As shown, the servo amplifier 3 includes a proportional element 30 having a proportional sensitivity K _p , an integral element 31 having a gain K _i , and a differentiating element 32 having a gain K _d between a pair of adders 33 and 34. A PID calculator 3a provided and a proportional element having an proportional sensitivity k _p0 on the output side thereof.
35 and a PD calculation unit 3b in which a differential element 37 having a gain k _d0 is arranged in parallel between a pair of adders 38 and 39.

The PID calculator 3a is a main part for determining the control amount of the hydraulic servo valve 20 which is a direct control target, and the rotation speed command signal E _s input to the servo amplifier 3.
Is given to the adder 33 of the PID calculator 3a. Adder 33
Also, the rotational speed feedback signal E _N corresponding to the rotational speed N _o of the output shaft 13 is applied through filter 40, the adder 33, both of the deviation signal (= E _s -
E _N ) is output to the proportional element 30 and the integral element 31.

On the other hand, the rotational speed feedback signal E _N is supplied to the differential element 32 arranged in parallel with the proportional element 30 and the integral element 31.
Are directly given to the output side of the adder 34
In the PI calculation value of the difference signal by the proportional element 30 and the integral element 31, PID calculation is performed to decrease correction by differential calculation value of the rotational speed feedback signal E _N by differential element 32, the hydraulic servo valve 20 The controlled variable E ₀ is determined.

The PID calculation unit 3a and the PD calculation unit 3b as described above
A control mode changeover switch 41 and an upper limit limiting circuit 42 are provided between and. The adder 38 of the PD calculation unit 3b has a rotation speed command signal E _s or PI input to the servo amplifier 3
Any one of the control amounts E ₀ output from the D calculation unit 3a is given through the upper limit limiting circuit 42 in accordance with the changeover of the changeover switch 41 to both a and b contacts. Note that the a contact of the changeover switch 41 is provided when the position control is used alone.

The adder 38 also receives either the displacement feedback signal E _x corresponding to the detection result of the displacement detector 23 or the torque feedback signal E _T corresponding to the detection result of the torque detector 15 as a filter 43. Are given through. The displacement feedback signal E _x and the torque feedback signal E _T are selected by the switching operation of the changeover switch 7. This switching is generally made according to the type (wet type or dry type) of the test clutch C, and in the case of a dry clutch requiring a complicated link system for engagement, the torque feedback signal E _T is Conversely, in the case of a wet clutch, the displacement feedback signal E _x
Is selected. The following description refers to the case where the displacement feedback signal _Ex is selected.

The adder 38 has a deviation (= E ₀ −
E _x or E _s −E _x ) is obtained and the result is output to the proportional element 35. The a-contact of the changeover switch 41 is necessary for performing the initial adjustment of the PD computing unit 3b, and is switched to the b-contact side during the characteristic test.
The input to 35, the deviation signal between the output serving E ₀ of the PID computing unit 3a and the rotation displacement feedback signal E _x (= E ₀ -
E _x ).

On the other hand, the displacement feedback signal _Ex is directly given to the differentiating element 37 of the PD calculating section 3b, and in the adder 39 on the output side, the proportional element 35 is provided.
The PD computing the P calculated value of the deviation signal to decrease correction by differential calculation value of the displacement feedback signal E _x by differentiating element 37 is carried out, the result is given as the control signal to the hydraulic servo valve 20 according to.

The conversion constant H ₀ of the displacement detector 23 is such that the displacement feedback signal E _x obtained as the output of the displacement detector 23 has a level corresponding to the rotation speed command signal E _s or the controlled variable E ₀ . It is set so that subtraction is possible. The displacement detector 23 is configured to detect the displacement x of the hydraulic cylinder 21 from a predetermined reference position (center position) in both directions (variation transformer type position converter, etc.), and the displacement feedback signal _Ex is positive or negative. 5 in FIG.
As indicated by a broken line therein, a constant value adding circuit 44 is arranged on the output side of the displacement detector 23, and the rotation speed command signal E _{s which} is always a positive voltage signal and the output (= E ₀ ) of the PID calculation unit 3a are provided. It is necessary to deal with.

Similarly, the conversion constant H of the F / V converter 9
₂ also outputs the rotation speed feedback signal E
_N is the rotation speed command signal E to be subtracted by the adder 33
Must be set to correspond to _s . However, the rotational speed N _o of the output shaft 13, the engine 10 as a driving source, type of clutch C to be tested, in order to respond to very different shift range according to the test conditions, a conversion constant H ₂ is variable It is necessary to use a certain F / V converter 9.

As is apparent from FIG. 4, the PD computing section 3b corresponds to the adjusting means 2 which is composed of the hydraulic servo valve 20 and the hydraulic cylinder 21 and is represented as a secondary delay element, and has responsiveness and damping characteristics. It becomes easy to improve the adjustment. That is, the control amount E _{0 is} controlled by the configuration of the PD calculation unit 3b.
The transfer function G ₁ (= x / E ₀ ) of the minor loop, which receives as input and outputs as displacement x, is as shown in the following equation.

[0042]

[Equation 1]

As is apparent from the equation (1), by including the PD computing section 3b, the transfer function G ₁ of the minor loop up to the adjusting means 2 can be represented as a quadratic delay system. In this way, the PD computing unit 3b acts as a delay compensation element for the adjusting means 2, and the deviation between the control amount E ₀ given as the target value and the displacement feedback signal E _x (corresponding to the displacement x) is large. In the meantime, the displacement x is steeply generated according to the result of the P calculation by the proportional element 35, and thereafter, the displacement feedback signal E in the differential element 37 is generated.
Results decreasing correction by differential operation value of _x is carried out, the displacement x
The rate of change of the control signal becomes gradual, and the target value corresponding to the control amount E ₀ can be quickly settled, and the optimization of damping can be achieved.

Even when the torque feedback signal E _T is used in place of the displacement feedback signal E _x , the displacement x, which is the output of the adjusting means 2, is maintained until the axial torque T _c on the output side of the clutch C is reached. Transmission element (pressure regulating valve 18
Since the clutch C) and the clutch C) are proportional elements, as is apparent from FIG. 4, the PD computing unit 3b having the same configuration can deal with them.

As described above, the PD calculation unit 3b is a hydraulic servo valve.
This is necessary when the adjusting means 2 having the 20 and the hydraulic cylinder 21 and exhibiting the behavior as a second-order lag system is used as described above, and the adjusting means 2 that behaves as a proportional element (actually exists. If it is difficult to use), a PID calculation unit in which an integral element is arranged in parallel with the proportional element 35 is required.

On the other hand, the entire control system shown in FIG. 4, that is, the clutch C according to the rotational speed command signal E _s given from the outside.
There changing the engagement strength, inertia disc 14 against the load torque T _b of the test load B by a shaft torque T _c which is obtained from an output shaft 13 of the clutch C is rotated, the rotation of the output shaft 13 It is assumed that the transfer function G (= N _o / E _s ) of the main loop until it appears as the speed N _o is a proportional element in which the position control section (or torque control section) has a proportional sensitivity K _1. When it is introduced, that is, in the frequency region sufficiently lower than ω _n1 (= 2πf ₁ ), the following expression is obtained.

[0047]

[Equation 2]

As is clear from the equation (2), when ω _n1 is made relatively large enough to collect the minor loops, the PID
By including the calculation unit 3a, the transfer function G of the main loop
Also, as a result of being expressed as a second-order delay system in the frequency region of ω << ω _n1 , the PID calculation unit 3a acts as a delay compensation element of the entire control system. That is, when there is a deviation between the rotation speed command signal E _s which is the control target and the rotation speed feedback signal E _N (corresponding to the output rotation speed N _o ) obtained as a result of the control, the proportionality is initially set. As a result of the PI calculation by the element 30 and the integration element 31, the control amount E ₀ output from the PID calculation unit 3b changes abruptly, while the differential element
As a result of the reduction correction by the differential operation value of the rotation speed feedback signal E _N in 32, the degree of change of the control amount E ₀ is as the rotation speed feedback signal E _N approaches the rotation speed command signal E _s and the deviation becomes smaller. Becomes loose.

Thus, the rotation speed N ₀ of the output shaft 13 can be quickly settled to the target speed corresponding to the rotation speed command signal E _s , and high responsiveness and damping optimization can be achieved. Even if the output rotation speed N ₀ fluctuates due to a disturbance thereafter, the speed is quickly returned to the predetermined target speed, and the constant speed state can be accurately maintained.

That is, in the characteristic test of the clutch C performed by using the device of the present invention as described above, a predetermined load torque T _b is set to the test load B and the clutch C is slid and engaged. The output rotation speed N _o can be kept constant with high precision. Therefore, the test process for evaluating the durability of the friction plate of the clutch C performed after this, specifically, the load torque T _b of the test load B is released, and the engagement of the clutch C under the sliding engagement is released. The process of increasing the resultant force and accelerating the inertial disk 14 connected through the output shaft 13,
Results is started at as uniform as possible initial conditions, the time to completion of the engagement, and characterization of the output speed N _o friction plate based on a comparison of the change in state of the meantime is, investigator Highly accurate test results can be obtained without requiring the skill of a person.

The device of the present invention further comprises the characteristic calculating section 5. As described above, the characteristic calculation unit 5 detects the engaging force signal E _p corresponding to the clutch oil pressure P _c by the operating force detector 28, the torque detector 15, and the axial torque of the output shaft 13. The torque feedback signal E _T corresponding to T _c is detected by the rotation speed detector 16, the input rotation speed signal E _i corresponding to the input rotation speed N _i of the clutch C, and the rotation speed detector 17, and the clutch C is detected. The rotational speed feedback signals E _N corresponding to the output rotational speed N _o of the respective are given.

FIG. 6 is a block diagram showing the internal structure of the characteristic calculating section 5. The rotation speed feedback signal E _N input to the characteristic calculator 5 is given to the adder 50.
Further, the input rotation speed signal E _i is given to the adder 50 via an amplifier 51 (gain α) arranged in the preceding stage of the adder 50. The adder 50 obtains the both input deviation (= αE _i -E _N), and outputs the result to the multiplier 52. This deviation becomes zero when the input rotation speed N _i and the output rotation speed N _o are synchronized, that is, when the engagement of the clutch C is completed.

The torque feedback signal E _T input to the characteristic calculating section 5 is also input to the multiplier 52 via the amplifier 53 (gain β), the absolute value circuit 54, and the proportional element 55. The absolute value circuit 54 is a circuit for converting the torque feedback signal E _T given with a negative sign into a positive value, and the proportional sensitivity of the proportional element 55 is the reciprocal of the gear ratio i of the transmission 12. . With this configuration, the input to the same side of the multiplier 52 corresponds to the input torque of the clutch C, and the physical meaning of the output of the multiplier 52 is the input rotation speed N _i and the output rotation speed N _o . The deviation is multiplied by the input torque, that is, the friction work per unit time in the clutch C under the sliding engagement.

The output of multiplier 52 is provided to proportional element 56. The proportional sensitivity of the proportional element 56 is the reciprocal of twice the product of the area a of the friction plates of the clutch C and the number Z (because friction occurs on the front and back sides of each friction plate), and the output of the proportional element 56. Can be taken out from the first output terminal O ₁ . The output of the proportional element 56 is also given to the integrator 57 and the zero cross detector 58, and the outputs of both of them can be taken out from the second and third output terminals O ₂ and O ₃ , respectively. is there.

The output of the multiplier 52 is the friction work of the clutch C per unit time, and the output obtained at the first output terminal O ₁ by multiplying this by the above-mentioned proportional sensitivity of the proportional element 56 is the clutch C. The friction work rate E _AT per unit area of the friction plate. The output obtained at the second output terminal O ₂ is the time integrated value of the friction power E _AT , that is, the total friction work E _A of the friction plate of the clutch C. Further, the output obtained at the third output terminal O ₃ is due to the characteristic of the zero-cross detector 58 sensitive to the zero-cross time of the input signal, that is, the time when the friction power E _AT crosses zero, that is, the clutch C.
A pulse signal (engagement completion signal) that shifts to a predetermined high level (TTL level) at the time of completion of engagement in which the driving-side and driven-side friction plates become synchronous at a constant speed.

On the other hand, the output of the proportional element 55 corresponding to the input torque of the clutch C passes through the proportional element 59 and the divider 60.
Is given to. The proportional sensitivity of the proportional element 59 is the reciprocal of the product of the number Z of friction plates of the clutch C, the effective diameter D _m, and the pressure receiving area A _c of the working piston of the clutch C.
The input from 59 to the divider 60 is a frictional force generated at each friction plate of the clutch C.

An engagement operation force signal E _p corresponding to the clutch oil pressure P _c is also input to the divider 60 via an amplifier 61 and a constant value subtraction circuit 62 with a lower limit. amplifier
Reference numeral 61 is a fixed gain amplifier that multiplies the engagement operating force signal E _p by a predetermined gain, and the output of the amplifier 61 is subtracted by the stationary subtraction circuit 61 from the equivalent value of the equivalent piston return pressure P _r. If the result is negative, it is limited to zero and input to the divider 60. That is, the physical meaning of this input process is the net effective pressure applied to each friction plate of the clutch C for engagement.

The divider 60 operates to divide the input from the proportional element 59 by the input from the constant value subtracting circuit 61, and the result can be taken out from the fourth output terminal O _4. . Since both inputs to the divider 60 have the above-mentioned physical meanings, the fourth output terminal O
_The output obtained in ₄ is the average dynamic friction coefficient μ _{m of} the plurality of friction plates built in the clutch C.

FIG. 7 is a time chart showing an example of the changing state of each input and output of the characteristic calculating section 5 during the characteristic test performed by the above-mentioned procedure. In the figure, the horizontal axis indicates time, and t ₀ is the time when the clutch C starts the sliding engagement. The input rotation speed N _i decreases starting from the initial speed n ₀ at the start of engagement, and the output rotation speed N _i also decreases.
_{The value of o} rises from 0 as a starting point and reaches the target speed n ₁ under sliding engagement to settle. As shown in the figure, this settling to n ₁ is quickly realized with little overshoot, and the fluctuation after settling is extremely small. This is realized by the above-mentioned configuration of the servo amplifier 3.

After the sliding engagement state of the clutch C is continued for a predetermined time, at t ₁ , the load torque T _b of the test load B is released, the engaging force of the clutch C is increased, and the output shaft 13
Output rotational speed N _o accelerate the inertia disc 14 which is connected via a test to examine the time to reach the predetermined speed n ₂ is performed. This is achieved by rapidly until the oil pressure to give the clutch oil pressure P _c in normal engagement, as shown, the axial torque T _c and the rotational speed of the output shaft 13 with an increase in the clutch oil pressure P _c n _o both surge, the input rotation speed n _i is settled to the initial speed n ₀ engagement is completed.

During this period, the friction work rate E _AT , the total friction work E _A, and the dynamic friction coefficient μ _m in the friction plate of the clutch C are output by the output terminals O ₁ , O ₂ and O ₄ of the characteristic calculating section 5 respectively. The characteristics of the friction plate can be quantitatively evaluated with high accuracy by monitoring the output, and the reliability of the test result is improved.The test result can be used for designing the friction plate. By reflecting it, it becomes possible to contribute to the optimization of the size of the transmission system by the size reduction of the clutch C.

Further, in the apparatus of the present invention, the output of the zero-cross detector 58 sensitive to the zero-cross of the friction power E _AT is obtained at the output terminal O ₃ of the characteristic calculating section 5 as shown in the lowermost part of FIG. , The time required to complete the engagement, which is a particularly important factor in the characteristic evaluation of the friction plate, is the time between the time t _{2 at} which the output changes to a high level and the time t _{1 at} which the transition to full engagement is accelerated. Therefore, it is possible to specify with high accuracy without error, and it becomes possible to realize durability evaluation based on this result with high accuracy.

The shaft torque T _c of the output shaft 13 becomes substantially zero after the end of acceleration. Further, the rotation speed N _o decreases as shown in the figure with the loss of the clutch oil pressure P _c , and returns to the state before the start of the test. Further, the total friction work E _A obtained at the output terminal O ₂ is due to the reset discharge of the integrator 57, and the voltage signal corresponding to the dynamic friction coefficient μ _m obtained at the output terminal O ₄ is the axial torque T at the time of zero crossing. _{Since c} becomes substantially zero, the state before the test is restored at the time point indicated by t _{2 in} FIG.

[0064]

As described above in detail, in the device of the present invention, the rotation speed obtained at the output side of the clutch is fed as a feedback signal to the servo amplifier which controls the engagement operation of the clutch to be tested. By determining the control signal to be given to the adjusting means for correcting the engaging speed of the clutch by correcting the rotation speed command signal by
The rotation speed on the output side in the sliding engagement state, which is necessary for the characteristic test, can be accurately maintained at a constant level, and the initial conditions and boundary conditions for subsequent engagement strengthening are made constant until the engagement is completed. It is possible to improve the reliability of the test result, including the evaluation of durability performed according to the time.

Further, the servo amplifier corrects the PI calculation value, which receives the deviation between the rotation speed feedback signal and the rotation speed command signal, by the differential value of the rotation speed feedback signal to determine the control amount of the adjusting means. Since the unit is provided, the output side rotation speed can be maintained with higher accuracy under the sliding engagement state, and the reliability of the test result is further improved.

Further, the displacement of the adjusting means or the shaft torque on the output side of the clutch is detected, and a proportional operation value, which receives as an input the deviation between the feedback signal corresponding to the detection result and the output of the PID operation section, of the feedback signal. P to obtain an operation control signal which is corrected by the differential value and is given to the adjusting means.
Since the D calculation unit is provided, the delay of the adjusting means is absorbed, the rotation speed on the output side can be maintained at a higher precision and constant, and the initial adjustment for optimizing the control system can be easily performed.

Furthermore, the rotational speed of the input side and the output side of the clutch to be tested, the axial torque of the output side, and the engaging operation force of the clutch are detected, and the detection results are used to detect the friction plate. Since the characteristic calculation unit that calculates and sequentially outputs the characteristic value related to the frictional behavior is provided, the characteristic evaluation of the friction plate is quantitatively performed, does not require skill, and there is no possibility that individual differences occur. It enables error-free characterization.

Further, since the friction power per unit area of the friction plate is included as one of the characteristic values to be calculated by the characteristic calculation unit, and the zero crossing point of this friction power is detected, It is possible to accurately detect the time required to complete the engagement from the detection results, and it is possible to realize highly accurate durability evaluation, which is particularly important when evaluating the characteristics of the friction plate, and the obtained test results can be used to design the friction plate. By reflecting this, the present invention has excellent effects such as contributing to the achievement of optimization of the size of the transmission system including the clutch.

[Brief description of drawings]

FIG. 1 is a schematic view showing a test execution state by the device of the present invention.

FIG. 2 is a model diagram showing the overall configuration of the device of the present invention.

FIG. 3 is a schematic view showing an example of adjusting means.

FIG. 4 is a block diagram showing an overall configuration of a control system of the device of the present invention.

FIG. 5 is a block diagram showing an internal configuration of a servo amplifier.

FIG. 6 is a block diagram showing an internal configuration of a characteristic calculation unit.

FIG. 7 is a time chart showing an example of a change state of each input and output of the characteristic calculation unit during the characteristic test by the device of the present invention.

[Explanation of symbols]

 2 Adjusting means 3 Servo amplifier 3a PID calculation unit 3b PD calculation unit 5 Characteristic calculation unit 6 F / V converter 9 F / V converter 10 Engine 13 Output shaft 14 Inertial disk 15 Torque detector 16 Rotation speed detector 17 Rotation speed detection 18 Pressure regulator 20 Hydraulic servo valve 28 Operating force detector 30 Proportional element 31 Integral element 32 Differential element 35 Proportional element 37 Differential element 52 Multiplier 57 Integrator 58 Zero cross detector 60 Divider B Test load

Claims (6)

[Claims] 1. An output side of a clutch for disconnecting an input from a rotary drive source is connected to a test load through an inertial body, and slips between friction plates of the clutch under a predetermined load condition of the test load. After obtaining the engaged state, the load is released and the engaging operation force of the clutch is increased to accelerate the inertial body, and the engagement completion time until the input rotational speed from the rotary drive source is reached is measured. Then, in the characteristic test device of the clutch friction plate for performing the characteristic evaluation including the durability of the friction plate based on this result, a substantially linear displacement is generated in accordance with an electric control signal, and the engagement operating force of the clutch is generated. Adjusting means for adjusting the rotation speed, a rotation speed detector for detecting the rotation speed on the output side of the clutch, and correcting the rotation speed command signal based on the rotation speed feedback signal corresponding to the detection result, motion A characteristic test device for a clutch friction plate, comprising: a servo amplifier that outputs a control signal. 2. The PID in which the servo amplifier has a PI calculator that receives a deviation between the rotation speed command signal and the rotation speed feedback signal and a differentiator that receives the rotation speed feedback signal in parallel. The device for testing a characteristic of a clutch friction plate according to claim 1, further comprising a calculation unit. 3. A displacement detector for detecting the displacement of the adjusting means is provided, and the servo amplifier receives a deviation between an output of the PID calculator and a displacement feedback signal corresponding to a detection result of the displacement detector. The clutch friction plate characteristic testing device according to claim 2, further comprising: a PD computing unit in which a differentiator that receives the displacement feedback signal is provided in parallel with the proportional computing unit. 4. A torque detector for detecting the shaft torque on the output side of the clutch is provided, and the servo amplifier has the P
PD computing unit comprising a proportional computing unit having a deviation between an output of the ID computing unit and a torque feedback signal corresponding to a detection result of the torque detector as an input, and a differentiator having the torque feedback signal as an input. The characteristic test device for a clutch friction plate according to claim 2, further comprising: 5. An output side of a clutch for engaging and disengaging an input from a rotary drive source is connected to a test load via an inertial body, and slips between friction plates of the clutch under a predetermined load condition of the test load. After obtaining the engaged state, the load is released and the engaging operation force of the clutch is increased to accelerate the inertial body, and the engagement completion time until the input rotational speed from the rotary drive source is reached is measured. Then, in the characteristic test device of the clutch friction plate for performing the characteristic evaluation including the durability of the friction plate based on this result, the rotation speed detector for detecting the rotation speed of the input side and the output side of the clutch, respectively, An operating force detector that detects the engagement operating force of the clutch, a torque detector that detects the shaft torque on the output side of the clutch, and characteristic values related to the frictional behavior of the friction plate using the respective detection results. And calculate A characteristic test device for a clutch friction plate, comprising: a characteristic calculation unit that outputs the next. 6. The characteristic calculating section includes means for calculating a frictional power per unit area of the friction plate, means for detecting a zero crossing time point of the output of the means, and the coefficient based on the detection result. The device for testing the characteristics of a clutch friction plate according to claim 5, further comprising means for specifying a time required until completion of engagement.