JPS58219434A - Testing apparatus for power steering device - Google Patents

Abstract

PURPOSE:To perform various performance tests efficiently, by equalizing a command load signal corresponding to the steering angle, which is detected by a cylinder of a load means and the load signal, which is detected by a load gage, and controlling fluid supplied to the cylinder. CONSTITUTION:A switch 53 is switched to a proportional load mode M1, and a first command load generating circuit 51 is made to be effective. A command load Fc, which is proportional to a rotary angle of a steering wheel, is imparted to an operation control part 40, and made to be equal to a detected load Fd detected by a load gage 31. Pressure fluid to a cylinder 15 is controlled by a servo valve 37. In this way, input and output characteristics can be tested in the mode M1. When the switch 53 is switched to a constant load mode M2, a second command load generating circuit 52 becomes effective. By the adjustment of variable resistors R1, R2, R3, and R4, the tests such as engaging characteristics of gears at various constant load levels can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a performance testing device for a power steering device for an automobile.

Conventional test equipment for testing the performance of power steering devices (hereinafter simply referred to as steering devices) is equipped with spring loading means such as coil springs or torsion bars, which apply loads according to displacement or swing angle. I was investigating the input/output characteristics of the steering gear.

Such spring-type loading means can only apply a proportional load, and when testing different types of steering devices, it is necessary to change the applied load characteristics, and the characteristics vary depending on the steering device. I had to replace it with a spring. In addition, the meshing state of the rack and pinion, the frictional resistance of the piston and piston rod seals, and the seal characteristics must be measured by displacing the rack bar over the full stroke between the left and right ends with the hydraulic oil in the cylinder at a constant pressure. However, such tests are almost impossible with conventional loading methods.

In view of these points, the present invention allows load characteristics suitable for various power steering devices to be arbitrarily applied, and also allows constant loads to be applied in areas other than proportional loads and the vicinity of the neutral position. The purpose of this test is to enable various performance tests.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 10 denotes the ease of the test device, and on this base 10 there is a fixed base 11 for fixing the steering device 20, and a pair of rocking arms with a knuckle arm 12 protruding from the base 10 and capable of rocking around the vertical axis. Support stand 14 supporting the upper and lower ends of member 13.13
．． 14 and a support 16.16 which supports a cylinder 15.15 as a loading means is mounted and fixed.

The steering device 20 includes, for example, a gear box 21 that houses a rack and a pinion that mesh with each other, a servo valve device 22 that is linked to the rotation of the pinion shaft, and a power cylinder 23 that is coaxially provided with the rack bar. Although the steering device is a rack and pinion type, the type of steering device is not limited to this.

The gearbox 21 and the power cylinder 23 are clamped onto the fixed base 11 by clamping members 24.24.

Tie rods 25 and 25 are connected to both ends of the rack bar via ball joints, and are connected to a knuckle arm 12 that projects from the swinging member 13. The position of the mounting base 12a of this knuckle arm 12 can be adjusted along a mounting surface 13a parallel to the axis of the swinging member 133-, so that a predetermined tie rod angle can be set. The swinging member 13.13 has knuckle arms 12, 12.
In the opposite direction, a load coupling arm 17.17 is connected to the piston rod 15a of the cylinder 15 as a load means by a projecting sill. A support member 2'7.27 is provided on the support body 16 that supports the cylinder 15.15 and is pivotably supported on a horizontal support shaft 26, and the cylinder 15 is pivoted on this support member 2'7.27 on a vertical support shaft 28. Possibly supported. Therefore, the cylinder 15 is allowed to swing both in the horizontal plane and in the vertical plane. The support bracket 18 that supports the upper end of the swinging member 13 is provided with a potentiometer 30 for detecting a steering angle, and the rotating shaft of the potentiometer 300 is connected to the swinging member 13. It is also effective to provide a displacement detector that detects the amount of displacement of the piston rod of the cylinder 15 in place of the potentiometer 30 for detecting the steering angle.

A load meter 31 for load detection is interposed between the tie rods 25 and 25, and the axial force acting on the tie rods, that is, the load, is detected. A handle 35 is connected to an input shaft 36 of the 4-servo valve device 22 that is connected to the pinion shaft.

The control means for varying the load generated by the cylinders 15.15 will now be described. In FIG. 2, an electro-hydraulic servo valve 37 is connected to the cylinder 15, and a pressure fluid supplied from a pressure fluid source 38 is supplied to the servo valve 3.
The control is performed according to a control signal S given to 7. This control signal S is a command load II'C corresponding to the handle rotation angle θ detected by the potentiometer 30.
On the other hand, the calculation control section 40 controls the detected loads Fa detected by the load meter 31 to be equal to each other. The command load input terminal 41 of the calculation control unit 40 is connected to a first command load generation circuit 51 configured with a calculation amplifier that outputs a voltage proportional to the output of the potentiometer 30, and a first command load generation circuit 51 that outputs a voltage proportional to the output of the potentiometer 30. A second command load generation circuit 5 outputs a voltage proportional to , and at a constant level in other areas.
2 are connected via a changeover switch 53.

The configuration of the first command load generation circuit 51 is shown in FIG. 3, and the configuration of the second command load generation circuit 52 is shown in FIG. Arithmetic control unit 4
The output of the load meter 31 inserted into the tie rod 25 is inputted to the detected load input terminal 42 of No. 0 via the amplifier 32.

In such a configuration, if the selector switch 53 is switched to the proportional load mode M1, the first command load generation circuit 51 becomes effective and a command load FC proportional to the steering wheel rotation angle is given to the calculation control section 40. The pressure fluid is controlled by the servo valve 37 to the cylinder 15 so that the detected loads 'Fd detected at the cylinders 15 and 15 become equal. In the proportional load mode M1, the input torque applied to the handle is separately detected, the detected load Fd obtained from the load cell 31 is used as the output, and the relationship between the input torque and the output is expressed as X-Y.
The input/output characteristics can be tested by recording on a recorder. Furthermore, by changing the amplification gain of the operational amplifier OPI shown in Fig. 3 using the variable resistor Rf, the ratio between the steering wheel rotation angle and the tie rod load load can be changed arbitrarily, and the load suitable for various power steering devices can be changed. Testing in mode is easy.

When the changeover switch 53 is switched to the constant load mode M2, the second command load generation circuit 52 becomes effective, and the load changes proportionally near the neutral position of the steering wheel, and becomes a constant load beyond a certain range.

The level of this constant load can be changed arbitrarily by using the variable resistance shown in Figure 4, and tests can be performed on gear meshing characteristics, seal sliding resistance, and seal function under various constant load levels. It can be performed.

The test device according to the present invention is provided with a cylinder as a load means, detects a steering angle, and generates a command load signal according to the steering angle, so that this command load signal and a detected load signal detected by a load meter become equal. The cylinder supply fluid was servo controlled as shown in 1.
Even if a common load means is used, the load mode for the handle rotation angle can be changed as appropriate, and various performance tests can be performed efficiently on one test stand. In addition, in the proportional load mode, the ratio between the handle rotation angle and the load can be changed arbitrarily by adjusting the amplification gain by operating the operational amplifier knob, and the load characteristics suitable for various power steering devices can be changed. can give. Even in the constant load mode, the level of the constant load can be easily adjusted by operating the knob, and it becomes a proportional load near the neutral position, and furthermore, it is possible to apply a constant load with the direction of the load reversed in the left and right areas, so it is possible to easily adjust the level of the constant load by operating the knob. It has the advantage of being able to effectively test seal characteristics, seal resistance, etc. by moving the piston over its full stroke.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view of the entire test device, FIG. 2 is a control block diagram of the load means,
Figure 3 is a diagram showing a specific example of the first command load generation circuit;
The figure is a diagram showing a specific example of the second command load generation circuit. DESCRIPTION OF SYMBOLS 10... Base, 11... Fixed base, 12... Knuckle arm, 13... Swinging member, 15... Cylinder, 20... Power steering device, 25... Tie rod, 3
0... Potentiometer, 31... Load meter, 8- 37... Servo valve, 40... Arithmetic control unit, 51...
- First command load generation circuit, 52... second command load generation circuit. Patent applicant Toyota Machinery Co., Ltd.

Claims (3)

[Claims] (1) A swinging member that is connected to the power steering device to be tested via a tie rod and a knuckle arm and is supported for swinging movement, and a cylinder that is coupled to a load connecting arm that projects from the swinging member. and a pressure fluid source that supplies pressure fluid to the cylinder; and an electrohydraulic servo valve that controls the pressure fluid supplied from the pressure fluid source according to a control signal.
a steering angle detector that detects a steering wheel rotation angle or a displacement amount of an element constituting the steering system; a first command load generating means that outputs a load signal proportional to the detected angle obtained from the steering angle detector; a second command load generating means that outputs a load signal that is proportional to the detected angle in the vicinity of the neutral position of the handle and is constant in a region other than the vicinity of the neutral position;
A selection switching means that enables either the first command load generation means or the second command load generation means, a load detection hand that detects the load that can be determined by the cylinder, and a selection switching means that enables the selection switching means. 1. A test device for a power steering system, comprising: an arithmetic and control unit configured to provide a control signal to the electro-hydraulic servo valve such that a load signal and a load detection signal are applied to the electro-hydraulic servo valve so that both signals match. (2) The first command load generating means includes an operational amplifier for amplifying the signal obtained from the steering angle detector, and a variable resistor for adjusting the amplification gain of the operational amplifier. The test device for the power steering device described above. (3) The second command load generation means has an operational amplifier that amplifies the signal obtained from the steering angle detector, and a limiter that adjustably sets the upper and lower limits of the amplified signal level of the operational amplifier. A test device for a power steering device according to claim 1.