JP4061778B2 - Friction coefficient variable device for chassis dynamometer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a friction coefficient variable device in a chassis dynamometer that changes a friction coefficient between a tire and a roller when testing an antilock brake of an automobile in the chassis dynamometer.
[0002]
[Prior art]
Twin roller chassis dynamometer load roller has a R _L and the free roller R _F, axis fly and dynamometer DY respectively of each load roller R _L which is rotated by the tire of the test vehicle W as shown in FIG. 10 Wheels are connected.
[0003]
As shown in FIG. 6 (a), the load W per vehicle is received by the load roller R _L and the free roller R _F , and the rollers R _L and R _F having the same diameter are provided at the same height. min load W _L and W _F to the roller R _L and R _F is equal. Further, also changes the roller R _L and R when changing the tire in contact with the height of the _F min load W _L and W _F as shown in Figure 6 (b).
[0004]
Examples of μ adjusting means for setting various friction coefficients μ equivalent to the road surface are shown in FIGS. In the μ adjustment means of FIG. 7, the load roller _RL is attached to one side of the base 102 via the receiving base 101, the roller _RF attachment side of the base 102 is formed thin, and the front and rear position can be adjusted with the adjustment screw 103 thereon. such a formed intermediate table 104, and the height adjustable free rollers through the adjustment screw 105 in the middle stage 104 R _F pedestal 106 provided, which adjusts the mu.
[0005]
The μ adjusting means shown in FIG. 8 fixes the rollers R _L and R _F to the movable cradle 203 and moves the position of the movable cradle 203 along the upper curved surface 202 of the mounting base 201 via the roller 204. Is adjusted.
[0006]
9 adjusts the load roller _RL receiving base 303 via the load cell 305 on the front wheel side movable frame 301 and the rear wheel side fixed frame 302 of the vehicle, and also sets the free roller _RF . The cradle 304 is placed side by side, and μ is adjusted by moving the movable frame 301 on the floor 305 in the front-rear direction while reading the value of the load cell 303.
[0007]
Further, the μ adjusting means in FIG. 10 is configured such that a pair of rollers R _L and R _F is installed on a moving table 401, the moving table 401 can be moved and adjusted by the moving device 402, and the free roller R _F is moved by the moving device 403. By enabling movement adjustment, μ is adjusted.
[0008]
[Problems to be solved by the invention]
The μ adjustment shown in FIG. 7 requires two adjusting screws to be adjusted in order to adjust the position of the free roller, and requires an intermediate base, which makes the structure complicated. In the μ adjustment shown in FIG. 8, both the movable table and the opposed surface of the movable table must be formed on a curved surface that is coaxial with the free roller, which is not easy to process and the movable table position adjusting mechanism is complicated. 9 and 10 is performed without changing the height of the load roller and the free roller, the adjustment range is narrow.
[0009]
The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a simple chassis dynamo friction coefficient variable device having a configuration capable of easily adjusting a wide range of μ without difficulty. It is in.
[0010]
[Means for Solving the Problems]
A friction coefficient variable device for a chassis dynamometer according to the present invention is a twin chassis dynamometer that includes a road roller and a free roller, sets a road surface friction resistance coefficient by changing the position of the free roller, and performs a vehicle running test.
Supports both ends of the free roller shaft so that it can move in a circular arc with a pair of arms having a fulcrum on the bottom,
The arm is moved by a drive device that is linked to the servo motor and screw jack to change the position of the free roller, and the intermediate lift driven by the intermediate lift drive unit between the position of the load roller and the free roller. It is characterized by having arranged .
[0011]
The pair of arms may be integrally connected with a square pipe, and the movable end of the screw jack and the square pipe may be connected with a link.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show a friction coefficient varying device section in a chassis dynamometer. In the figure, R _L is a load roller, R _L is a free roller, and both ends of the free roller R _F shaft are supported by a bearing box 1, which is supported by a bearing arm 2, and the bearing arm 2 is on the free roller side. A bearing arm mounting base 7 provided on the base 8 is supported at a fulcrum a so as to be swingable. The left and right bearing arms 2 are connected by a square pipe 3.
[0013]
A screw jack 5 that is operated by an AC servo motor 6 is provided near the upper left and right center load rollers of the free roller side base 8, and the left and right centers of the tip of the screw jack 5 and the side of the load roller of the square pipe 3 are provided. A link 4 is provided between the two.
[0014]
Fulcrum a of the bearing arm 2, when the the partial load W _F to partial load W _L and the free roller R _F side to FIGS. 4 (a) as shown in the load roller R _L side to be substantially equal provided the position of the vector line of partial load W _F, by generating a difference in partial load W _L and W _F by moving the free roller R _F around the fulcrum a, as shown in FIG. 4 (b) loading to adjust the W _L. This makes it possible to simulate the change in the friction coefficient μ that occurs between the roller tires. The position of the load roller _RL is adjusted by operating the screw jack 5 with the AC servo motor 6.
[0015]
In the figure, 11 is a bearing box of the load roller _RL , 12 is a load roller locking device, 13 is a mounting base, 14 is a load roller side base, 21 is an intermediate lift, and 22 is an intermediate lift for operating the intermediate lift. A drive unit, 31 is a pit cover, and PP is a rotation detector.
[0016]
Next, the operation of this chassis dynamometer will be described. A test vehicle (not shown) is carried in from the pit cover 31 on the right side of FIG. At this time, the load roller _RL and the free roller _RF are locked by the roller lock device 12 so that the vehicle drive wheels do not slip.
[0017]
Further, the intermediate lift 21 is operated so that the tire does not fall between the rollers R _L and R _F and is set at almost the same height as the top of the roller. The free roller R _F is set at an almost upper limit position. When the vehicle tire comes between the rollers R _L and R _F , the intermediate lift 21 is moved down by operating the drive unit 22, and the intermediate lift 21 is lowered to the lower limit so as not to interfere with the operation of the free roller R _F. deep.
[0018]
Then, in response to the road surface friction coefficient to be tested μ change the position of the free roller R _F. As shown in FIG. 5, the position of the free roller R _F is moved through the link 4 by moving the screw jack 5 up and down by an AC servo motor 6. The road roller _RL is completely fixed to a support base 12 having both end bearing bases 11 and fixed on the road roller side base 14.
[0019]
According to the above embodiment, free roller R _F is as shown FIG. 1 around the fulcrum a bearing arm 2 can travel arc, large variable load sharing ratio of the load roller R _L and the free roller in this position change Therefore, it is possible to test various road surface friction coefficients. Further, the road surface friction coefficient μ can be automatically set by associating the setting of the AC servo motor 6 with the road surface friction coefficient μ.
[0020]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained. (1) Since the setting of the road surface friction coefficient can be changed only by changing the angle of the bearing arm, the road surface friction coefficient can be easily set and controlled.
(2) The road surface friction coefficient can be automatically set by linking the AC servo motor and screw jack.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration of a roller portion of a chassis dynamometer according to an embodiment.
FIG. 2 is a front view showing a configuration of a free roller portion for the left wheel.
FIG. 3 is a plan view showing the configuration of the left wheel roller section.
FIG. 4 is an explanatory diagram of a circular motion of a free roller and a change in load.
FIG. 5 is an explanatory diagram of the structure of an arc motion portion of a free roller.
FIG. 6 is an explanatory diagram of a load on a roller portion of a normal twin roller chassis dynamometer.
FIG. 7 is a configuration explanatory diagram of a roller unit according to Conventional Example 1;
FIG. 8 is a configuration explanatory view of a roller unit according to a second conventional example.
FIG. 9 is a configuration explanatory view of a roller unit according to Conventional Example 3.
FIG. 10 is a diagram illustrating a configuration of a roller unit according to Conventional Example 4.
[Explanation of symbols]
R _L ... load roller R _F ... free roller 1 ... bearing box 2 ... bearing arm 3 ... square pipe 4 for connecting the bearing arm ... link 5 ... screw jack 6 ... AC servo motor.

Claims (2)

In a twin chassis dynamometer that has a road roller and a free roller, sets the road friction resistance coefficient by changing the position of the free roller, and performs a running test of the vehicle,
Supports both ends of the free roller shaft so that it can move in a circular arc with a pair of arms having a fulcrum on the bottom,
This arm is moved by a drive device that is linked to the servo motor and screw jack to change the position of the free roller, and the intermediate lift driven by the intermediate lift drive unit between the position of the load roller and free roller friction coefficient changing device in a chassis dynamometer, characterized in that it has disposed. 2. The friction coefficient variable device in a chassis dynamometer according to claim 1, wherein the pair of arms are integrally connected by a square pipe, and the movable end of the screw jack and the square pipe are connected by a link .

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