JP2006170772A - Brake testing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake testing device capable of performing a braking test with a high accuracy even in a brake device requiring a braking test at a low operation pressure. <P>SOLUTION: The brake testing device comprises a second amplifying circuit 30 at the rear stage of strain amplifiers 13 and 14 as a first amplifying circuit for amplifying the detected operation pressure of the brake device 25, and a changeover switch 33A for switching the second amplifying circuit 30 between insertion and un-insertion to a line at the rear stage of the strain amplifiers 13 and 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a brake test apparatus for testing brake performance of a vehicle such as an automobile.

  Conventionally, the above-described brake test apparatus has been proposed (see, for example, Patent Document 1 and Patent Document 2). In this type of brake test device, an inertia that moves as an equivalent weight of a vehicle is rotationally driven by a motor, the brake device is hydraulically controlled to give a brake torque, and a torque or an oil pressure measured by a torque sensor or a pressure sensor is set to a predetermined value. Various tests of the brake are performed by controlling the size.

2 and 3 are configuration diagrams of such a conventional brake test apparatus.
The brake test apparatus shown in FIGS. 2 and 3 is connected to a variable resistor 10, a switch 11, a servo amplifier 12, strain amplifiers 13 and 14, a changeover switch 15, and a hydraulic pump (not shown) to be opened and closed. Servo valve 16, servo cylinder 17 provided with servo valve 16, master cylinder 18, pressure sensor 19 that outputs a signal of a brake fluid pressure level generated according to the movement of servo cylinder 17, and torque arm 20 And a torque sensor 21 that outputs a load applied to the torque arm 20 during braking of the brake device 25 as a torque value, and a brake device 25.

The variable resistor 10 sets a brake operation pressure. A brake operation pressure set as a set value of the variable resistor 10 (hereinafter referred to as a set voltage) is applied to one input terminal of the servo amplifier 12 via the switch 11. Entered.
An output of a strain amplifier 13 or 14 to be described later is input to the other input terminal of the servo amplifier 12 via a changeover switch 15.
Each of the strain amplifiers 13 and 14 is a bridge type amplifier. The strain amplifier 13 amplifies the output of the torque sensor 21, and the strain amplifier 14 amplifies the output of the pressure sensor 19.
The changeover switch 15 switches between the output voltage of the strain amplifier 13 and the output voltage of the strain amplifier 14. The switched output voltage of the strain amplifier 13 or the strain amplifier 14 is input to the other input terminal of the servo amplifier 12. The

The servo amplifier 12 operates the servo valve 16 and holds the output value at a point where the set voltage and the output voltage from the pressure sensor 19 or the torque sensor 21 are balanced.
The servo valve 16 is interposed between the servo cylinder 17 and a hydraulic pump (not shown), and adjusts the inflow amount and outflow amount of hydraulic oil into the servo cylinder 17.
The master cylinder 18 operates in accordance with the movement of the servo cylinder 17 and generates a brake fluid pressure applied to the brake device 25.

Next, the operation of the brake test apparatus configured as described above will be described.
(1) First, the set voltage set by the variable resistor 10 is input to one input terminal of the servo amplifier 12 by turning on the switch 11. Here, it is assumed that a voltage of 3V is applied.
(2) At this time, for example, since the output voltage from the pressure sensor 19 is still 0 (zero) V, the output of the servo amplifier 12 becomes a current of (+), and the servo cylinder 17 is activated by the action of the servo valve 16. It moves to the left (towards the drawing), which is the pressing direction.

(3) When the servo cylinder 17 moves to the left side, the master cylinder 18 operates and brake fluid pressure is generated.
(4) The output voltage from the pressure sensor 19 increases in proportion to the brake fluid pressure. When the voltage reaches 3V, which is the same as the set voltage, the output current of the servo amplifier 12 becomes 0 (zero), and the servo cylinder 18 is in that position. Stop.
(5) If there is a deviation between the set voltage and the output voltage from the pressure sensor 19, the output current of the servo amplifier 12 works to correct it.

  Thus, the servo cylinder 18 is controlled in the pressurizing direction or the depressurizing direction by the difference between the set voltage and the output voltage from the pressure sensor 19. It should be noted that control can be performed as long as the control value can be converted into voltage regardless of whether the control target is hydraulic pressure or torque.

JP 2000-136974 A JP-A-9-236516

  By the way, in the conventional brake test apparatus, the linearity on the low frequency side of the operating pressure applied to the brake device 25 is not good, and the control in the low frequency of the operating pressure is limited to 200 to 300 kPa, especially in the low frequency range. There is a problem in that a braking test that requires a braking test with an operating pressure cannot be performed with high accuracy.

  To solve this problem, it is possible to improve the linearity in the low range of the operating pressure by increasing the gains of the strain amplifiers 13 and 14. However, when the gain is increased, the followability is improved. On the other hand, when the gain is too high, an overshoot increases when the braking change is large, for example, when the brake operation is started, and an oscillation state is caused in some cases. For this reason, the gain cannot be easily increased. Incidentally, if the gain is lowered, the oscillation state does not occur, but the followability deteriorates.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a brake test apparatus that can perform a braking test with high accuracy even in a brake apparatus that must perform a braking test with a low operating pressure. And

  The brake test apparatus according to the above (1) is a brake test apparatus that operates the brake device with a cylinder and applies an operation pressure corresponding to a brake setting signal to the brake device, and applies the operation pressure applied to the brake device. Operating pressure signal detecting means for detecting and outputting an operating pressure signal at a level corresponding to the detected operating pressure; first amplifying means for amplifying the operating pressure signal output from the operating pressure signal detecting means; A second amplifying means for further amplifying the operating pressure signal amplified by one amplifying means; an operating pressure signal output from the first amplifying means; or an operating pressure signal output from the second amplifying means. The cylinder is controlled in the pressurizing direction or the depressurizing direction according to the difference between the first selecting means for selecting any one of the above and the difference between the brake setting signal and the operation pressure signal selected by the first selecting means. Characterized by comprising a control means.

  The brake test apparatus according to (2) is the brake test apparatus according to (1), wherein a third amplifying unit that amplifies the brake setting signal and the brake setting signal itself or the third amplifying unit. Second selection means for selecting any one of the brake setting signals amplified in step (i), wherein the second selection means operates in conjunction with the first selection means, and When the selection unit selects the operation pressure signal output from the first amplification unit, the brake setting signal is selected, and the first selection unit selects the operation pressure signal output from the second amplification unit. When selected, the brake setting signal amplified by the third amplifying means is selected.

  The brake test apparatus according to (3) is the brake test apparatus according to (1) or (2), wherein the second amplification means and the third amplification means are each capable of adjusting an amplification factor. Means are provided.

  According to the brake test apparatus described in (1) above, since the operating pressure signal amplified by the first amplifying means is further amplified by the second amplifying means, the range of operating pressure applied to the brake is expanded, and the second The linearity at a low frequency is improved as compared with before using the amplification means. Thereby, in the case of a brake device that must be tested with a low operating pressure, a test with high accuracy is possible by using the second amplifying means. In particular, in a test with a low operating pressure, there is hardly any significant change in the follow-up property, so even if the gain is increased, the oscillation state does not occur.

  According to the brake test apparatus described in (2) above, the third amplifying means is used and the brake setting signal (set voltage value of pressure or torque) is changed in accordance with the use of the second amplifying means. Even if the second amplifying means is used, the same accurate control as before can be performed.

  According to the brake test apparatus described in (3) above, the correlation between the operation pressure signal and the brake setting signal is the same when the second amplification means and the third amplification means are used and when they are not used. Can be made.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a main part of a brake test apparatus according to an embodiment of the present invention. 1 that are the same as those in FIGS. 2 and 3 described above are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 1, the brake test apparatus according to this embodiment includes an amplifier circuit 30 at the subsequent stage of the strain amplifiers 13 and 14, and can adjust the set values (brake setting signals) for each of the hydraulic pressure and torque. Variable resistors 10A and 10B, an amplifier circuit 31 that amplifies a set voltage of hydraulic pressure or torque, a changeover switch 32 that switches between the variable resistor 10A and the variable resistor 10B, and outputs of the strain amplifiers 13 and 14 of the amplifier circuit 30 A change-over switch 33A for switching between insertion and non-insertion to the side line, and a change-over switch 33B for switching between insertion and non-insertion to the pressure / torque setting line of the amplifier circuit 31. Yes.

  Note that the torque sensor 19 or the pressure sensor 21 referred to in the present specification corresponds to the operating pressure signal detecting means. The strain amplifier 13 or 14 corresponds to the first amplifying means, and the amplifier circuit 30 corresponds to the second amplifying means. The changeover switch 33A corresponds to a first selection unit. The servo amplifier 12 and the servo valve 16 constitute control means. Further, the amplifier circuit 31 corresponds to a third amplifier, and the changeover switch 33B corresponds to a second selector.

  The changeover switch 32 operates in conjunction with the changeover switch 15, and when the changeover switch 15 is switched to the pressure sensor 19 side (a terminal side), the variable resistor 10A side (a Switch to the terminal side. This makes it possible to adjust the pressure setting voltage. On the other hand, when the changeover switch 15 is switched to the torque sensor 21 side (b terminal side), the changeover switch 32 is switched to the variable resistor 10B side (b terminal side) that enables adjustment of the torque setting voltage. This makes it possible to adjust the torque setting voltage.

Further, when the changeover switch 33A and the changeover switch 33B are also interlocked and both are switched to the a terminal side, the amplifier circuit 30 is inserted in the line on the output side of the strain amplifiers 13 and 14, and the amplifier circuit 31 sets the pressure / torque It is inserted in the track for.
Since the amplifier circuit 30 amplifies the output of the strain amplifier 13 or 14, the amplifier circuit 31 is used to change the set voltage of the pressure or torque accordingly. That is, when the amplifier circuit 30 is used, if the set voltage value of pressure or torque remains as it is, accurate control cannot be performed. Therefore, when the amplifier circuit 30 is used, a set voltage value of pressure or torque commensurate with it. It is necessary to change the setting. For this purpose, the amplifier circuit 31 is selected together with the amplifier circuit 30.

  The amplifier circuits 30 and 31 are both composed of an operational amplifier, a resistor, and a variable resistor, and gain adjustment is possible by the respective variable resistors 30A and 31A (corresponding to the adjusting means). Using variable resistors 30A and 31A, gain adjustment is performed so that the correlation between the pressure or torque setting voltage and the operation pressure voltage based on the sensor output is the same when the amplifier circuits 30 and 31 are inserted into the line and when they are removed. can do.

By amplifying the output of the strain amplifier 13 or 14 by inserting the amplifier circuit 30 in the line, the range of the operating pressure applied to the brake device 25 is widened, so that it is lower than before the amplifier circuit 30 is inserted. The linearity of is improved. That is, before the amplifier circuit 30 is inserted, the control in the low range of the operating pressure is limited to about 200 to 300 kPa, but the control at about 20 to 30 kPa is possible by inserting the amplifier circuit 30. become. As a result, in the case of a brake device in which a braking test must be performed with a low operating pressure, a braking test with high accuracy can be performed by inserting the amplifier circuit 30 in the line. In particular, in a braking test at a low operating pressure, there is hardly any significant change in the follow-up performance, so even if the gain is increased, the oscillation state does not occur.
Thus, by using the amplifier circuit 30 properly, it becomes possible to control from 20 to 30 kPa to 20 MPa (in the high region, 30 MPa is the limit).

  As described above, according to the brake test apparatus according to the present embodiment, the amplifier circuit 30 is provided in the subsequent stage of the strain amplifiers 13 and 14, and the amplifier circuit 30 is connected to the line in the subsequent stage of the strain amplifiers 13 and 14. Since the selector switch 33A for switching between insertion and non-insertion is provided, the operating pressure can be controlled in the range from 20 to 30 kPa to 20 MPa, and a braking test that requires a braking test with a low operating pressure can be performed with high accuracy. It can be performed.

  The present invention can be applied to a use in which a braking test is performed under the same conditions as when the braking performance of a vehicle such as an automobile is mounted on an actual vehicle.

It is a lineblock diagram of the principal part of the brake testing device concerning one embodiment of the present invention. It is a block diagram of the principal part of the conventional brake test apparatus. It is a front view of the conventional brake test apparatus.

Explanation of symbols

10A, 10B, 30A, 31B Variable resistance 12 Servo amplifier (control means)
13, 14 Strain amplifier (first amplification means)
15, 32 selector switch 16 Servo valve (control means)
17 Servo cylinder 18 Master cylinder 19 Pressure sensor (operation pressure signal detection means)
20 Torque arm 21 Torque sensor (operation pressure signal detection means)
25 Brake device 30 Amplification circuit (second amplification means)
31 Amplifying circuit (third amplifying means)
33A changeover switch (first selection means)
33B changeover switch (second selection means)

Claims (3)

A brake test device that operates a brake device with a cylinder and applies an operation pressure corresponding to a brake setting signal to the brake device,
An operation pressure signal detecting means for detecting an operation pressure applied to the brake device and outputting an operation pressure signal at a level corresponding to the detected operation pressure;
First amplification means for amplifying the operation pressure signal output from the operation pressure signal detection means;
Second amplifying means for further amplifying the operating pressure signal amplified by the first amplifying means;
First selection means for selecting either the operation pressure signal output from the first amplification means or the operation pressure signal output from the second amplification means;
Control means for controlling the cylinder in a pressurizing direction or a depressurizing direction according to a difference between the brake setting signal and the operation pressure signal selected by the first selecting means;
A brake test apparatus comprising: Third amplifying means for amplifying the brake setting signal;
Second selection means for selecting either the brake setting signal itself or the brake setting signal amplified by the third amplifying means,
The second selection means operates in conjunction with the first selection means, and the brake setting signal is selected when the first selection means selects an operation pressure signal output from the first amplification means. And when the first selecting means selects the operation pressure signal output from the second amplifying means, the brake setting signal amplified by the third amplifying means is selected. The brake test apparatus according to claim 1.   3. The brake test apparatus according to claim 1, wherein each of the second amplifying unit and the third amplifying unit includes an adjusting unit capable of adjusting an amplification factor. 4.

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