JPH0128442Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a multi-axis vibration device used to investigate the vibration characteristics of automobiles, etc.

A multi-axis vibration device reproduces the state of a car running on a road surface on a bench by vibrating a test product, such as a car, in any desired vibration mode in each direction, front and back, up and down, and left and right. vibration characteristics,
It is used to investigate the source of noise caused by vibration or the durability caused by vibration. In most of these multi-axis vibration devices, as shown in FIG. Add. For example, in a multi-axis vibration device 2 as shown in FIG. 2, a brake drum 4 and a tire mounting hub (not shown)
Directly overlap the specimen mounting jig (hereinafter simply referred to as the mounting jig) 3 side on the vibration device side and use the mounting hole 5 to screw the two together with a hub nut or hub bolt (both not shown). . One end of a front-rear load bar 6 that applies longitudinal input, one end of a left-right load bar 7 that applies horizontal input, and one end of a vertical load bar 8 that applies vertical input are respectively pivotally attached to this mounting jig 3. The tool 3 is vibrated in the front-rear direction X, the left-right direction Y, and the up-down direction Z. In such a multi-axis vibration device 2, the load W on the vehicle body side is applied to a point O (hereinafter simply referred to as a load point) on the center line l of the axle fixed to the mounting jig 3, and this load point O is configured to add input to . Normally, in order to regulate all movements of one point (load point in this case), inputs in the front/back, left/right, and up/down directions X, Y, and Z applied to this load point O, and inputs around the three axes of X, Y, and Z are required. moment of
It is necessary to regulate Mx, My, and Mz. However, in the case of the multi-axis vibration device 2 shown in Fig. 2, the load point O
It is only necessary to be able to input vibrations in the three-axis directions of X, Y, and Z, and the moment around the three axes can be
My and Mz may not be necessary. Regarding Mx,
By setting the force application points (planes) of the inputs Y and Z at positions corresponding to the grounding points of tires on an actual vehicle, it is possible to reproduce the moment state when the actual vehicle is running. Therefore, in the multi-axis vibration device 2 shown in Fig. 2,
The occurrence of rotational displacement due to these moments is prevented for Mz by increasing the rigidity of the specimen, and for My by increasing the rigidity of the vertical load bar 8 and the mounting jig 3. In particular, the mounting jig 3 is installed with the front and rear load bars 6 offset downward from the load point O (this offset prevents the front and rear load bars 6 from coming into contact with the fenders of the vehicle body). A large moment My is applied in the direction, that is, around the Y axis. In order to suppress this, the weight of the mounting jig 3 and the vertical load bar 8 tends to increase in order to ensure their strength, resulting in the inconvenience of reduced vibration performance. Furthermore, as shown in Fig. 3, the mounting jig 3 is provided with
Input devices 9 are provided to add Y and Z inputs, respectively.
There is a multi-axis vibration device 13 equipped with four load bars 9, 10, 11, 12 controlled by 01, 101, 111, 121. This multi-axis vibration device 13 has one more load bar than the one shown in FIG.
12, which provide inputs in the front-rear direction X and the left-right direction Y, and control the moment My around the Y-axis to be zero, thereby preventing rotational displacement of the mounting jig 3. In this case, there are disadvantages in that four input devices are provided, which makes the control thereof complicated, and there are many moving parts, which reduces the vibration excitation ability and increases the space required. Furthermore, as shown in FIG. 4, the multi-axis vibration device 1 has three load bars 14, 15, 16 each controlled by input devices 141, 151, 161 attached to the mounting jig 3.
There are 7. This multi-axis vibration device 17 has the advantage that the number of input devices and load bars is smaller than that shown in FIG. 3, making it relatively easy to control and requiring less space. However, as shown in FIG. 5, in this multi-axis vibration device 17, the load point O on the mounting jig 3
In contrast, a pair of front and rear load bars 14 and 15 (hereinafter simply referred to as load bars) provide input in the front and rear direction X and the vertical direction Z, but in reality both load bars 14 and 15 are operated. The inputs given by the longitudinal and vertical levers (hereinafter simply referred to as levers) 18 and 19 and their input devices 20 and 21 are at the intersection of the center lines l3 and l4 of both load bars 14 and 15 (hereinafter simply referred to as input points). Join P. The multi-axis vibration device 17 shown in FIG.
and the input point P coincide only in a specific case as shown in FIG. When vibrating in the X direction, or in the front-back, up-down direction
and the input point P. When the vibration only occurs in the vertical direction Z, the lines of action of the load W on the load point O and the input F on the input point P coincide, so that no inconvenience occurs. However, when vibration in the longitudinal direction X is applied, loads Wz and Wx are applied to the load point O,
When inputs Fz and Fx are applied to input point P, the lines of action of each force do not coincide, resulting in a force couple. If we consider this couple with the load point O, that is, the mounting jig 3 side as a reference, the moment My around the Y axis is the mounting jig 3 side.
This moment My increases as the offset amounts a and b of the input point P with respect to the load point O increase. In the multi-axis vibration device 17 shown in FIG. 4, in order to suppress the rotational displacement caused by the moment My around the Y axis generated in this way, conventionally, the brake on the specimen side is continuously operated during the vibration test. For this reason, if a large Y-axis moment My, that is, a large braking moment, acts on the brake side, there is a risk that the sample on the brake side may be damaged.

The purpose of this invention is to provide a multi-axis vibration device that can protect the sample side.

The multi-axis vibration device according to this invention includes a mounting jig that is removably fixed to the axle, a pair of load bars whose upper ends are pivotally connected to the mounting jig, and whose lower ends are arranged with their lower ends relatively spread apart. A left-right load bar has one end pivotally attached to a mounting jig, and the other end pivots to a left-right lever that operates as a lever around the base by an input device, and a left-right load bar pivoted to the lower ends of the pair of load bars, and , is equipped with a pair of levers that are lever-actuated at the center of the base by each input device, applies arbitrary vibration to the specimen by the input device, and also applies vibrations to both ends between the axle center position of the mounting jig and the base. The universal joints are attached and configured to be connected by an axially expandable connecting rod. Therefore, when a pair of load bars is input to the mounting jig, even if a moment is generated around the left and right axes including the axle center position due to the offset between the input point and the load point which is the axle center position, the connection The rigidity of the rod allows it to be held down, and there is no need for the specimen to operate the brake, thereby preventing inconveniences such as damage caused by the moment.

This invention will be explained below with reference to the accompanying drawings.

FIG. 9 shows a multi-axis vibration device 22 as an embodiment of this invention. This multi-axis vibration device 22 also uses the same members as those used in the multi-axis vibration device 17 shown in FIG. 4, and henceforth, the same members will be given the same reference numerals and their explanation will be omitted. When performing a vibration test on the vehicle body 1 as a specimen, the multi-axis vibration device 22 is attached to the mounting portions of all wheels or some of the wheels, depending on the purpose of the test. The multi-axis vibration device 22 attached to each mounting portion has the same configuration, and hereinafter, the multi-axis vibration device 22 attached to the left front axle side will be explained. Vehicle body 1
The front wheel mounting portion of the vehicle is comprised of a brake drum 23 that is rotatable around the axle, and this brake drum 23 has four hub bolts 24 protruding from it (see FIG. 10). For this purpose, four holes 25 for fitting hub bolts are formed in the mounting jig 3, and the brake drum 23 is fixed to the mounting jig 3 by the hub bolts 24 fitted in these holes 25 and the nuts 26 screwed into the holes 25. Ru. In addition, the mounting jig 3 has a connecting rod 29 that connects the mounting jig 3 and the fixed base 28 on the base 27 side.
can be installed.

As shown in FIG. 10, the connecting rod 29 is formed of a main body 30 with high rigidity and universal joints 31 and 32 connected to both ends of the main body 30, respectively. Each of the universal joints 31 and 32 is a constant velocity joint that has degrees of freedom in both the axis-perpendicular direction A and the axial direction B, and a connecting flange 31 is provided at the end of each universal joint 31 and 32
1,321 is installed. The universal joint 32 facing the fixed base 28 is bolted to the fixed base 28 via its flange 321, and the other universal joint 31 is connected to the mounting jig 3. That is, holes 312 similar to the four holes 25 on the mounting jig 3 side are formed in the flange 311 of the universal joint 31, centered on the shaft center line l1, and these four holes 312 protrude from the mounting jig 3. The brake drum 23, the mounting jig 3, and the flange 311 of the universal joint can be integrally fixed by fitting the brake drum 23 into the hub bolt 24 and tightening with the nut 26. In this case, the center line on the axle side, that is, the center line l2 of the brake drum 23, and the center line l1 on the flange 311 side fixed to the mounting jig 3 intersect and overlap on the surface of the mounting jig 3. Therefore, the load point O on the center line l2 of the brake drum 23 to which the load W on the vehicle body 1 is applied is located on the center line l1 of the flange. Due to the action of the two universal joints 31 and 32, such a connecting rod 29 follows the movement of the mounting jig 3 even if the mounting jig 3 is displaced in the longitudinal direction X and the vertical direction Z with respect to the fixed base 28. flange 311 can operate,
Moreover, the brake drum center line l2 on the mounting jig 3 side
Displacement due to the surrounding moment (this is the moment My around the Y axis with respect to the load point O) can be prevented.

In addition to this, the mounting jig 3 has a pair of load bars 1 at both ends of its lower part that provide input in the longitudinal and vertical directions X and Z.
4 and 15 are pins 33 (one not shown)
It is pivotally connected via. Further, at the center of the lower part of the mounting jig 3, there is a left-right load bar 16 supported almost horizontally.
is pivotally mounted via a horizontal pin 35 (10th
(see figure). A pair of levers 18 and 19 are pivoted to the lower ends of the pair of load bars 14 and 15, and are pivoted to a base frame 36 on the side of the base 27, and are lever-actuated by input devices 20 and 21, respectively. Furthermore, a left-right lever 39 is pivotally attached to one end of the left-right load bar 16 and is pivoted to a protrusion 37 on the base 27 side, and is lever-operated by an input device 38 . Each input device 2
0, 21, and 38 are equipped with electro-hydraulic servo mechanisms, and the direction and flow rate of pressure oil supplied to each hydraulic cylinder 201, 211, and 381 are controlled by servo valves controlled by a control circuit (not shown). The mounting jig 3 side can be vibrated in any manner in the three axial directions of X, Y, and Z.

The multi-axis vibration device 22 shown in FIG. 9 can operate the input devices 20, 21, and 38 to vibrate the vehicle body 1 at a desired frequency, amplitude, and vibration direction.
This allows the intended vibration test to be performed. in this case,
As shown in FIGS. 7 and 8, the mounting jig 3,
That is, when the vehicle body 1 side is excited by the multi-axis vibration device 22, the load point O on the brake drum center line l2 set on the mounting jig 3 and the pair of load bars 1
The input point P, which is the intersection of both the center lines l3 and l4 of Nos. 4 and 15, is shifted, and the offset amounts a and b vary between the two. Therefore, in the mounting jig 3, the load Wz, Wx of the vehicle body 1 that fluctuates in the vertical direction is applied to the load point O, and the input Fz, which is applied to the input point P in the opposite direction to the loads Wz, Wx, is applied to the load point O.
Fx is added to each, and a moment My (My=aFz+bFy) about the Y axis including the load point O is generated.
However, the connecting rod 29 is attached to the mounting jig 3, and the flange 31 on this connecting rod side
1 is mounted so that its center line l1 intersects the load point O on the mounting jig 3 side, so the moment My around the Y axis is reliably suppressed by the rigidity of the connecting rod 29, and The side will not undergo any rotational displacement due to the moment My. Therefore, there is no need to operate the brake system on the side of the car body 1 while performing a vibration test on the car body 1 on the multi-axis testing machine 22, which causes the inconvenience of damaging the test piece on the brake side as in the conventional case. is prevented.

The connecting rod 29 of the multi-axis vibrator 22 shown in FIG. 9 uses constant velocity joints having degrees of freedom in both the axis-perpendicular direction B and the axial direction A as a pair of universal joints 31 and 32. This connecting rod 29 with strong torsional rigidity can connect the mounting jig 3 that moves with the fixed base 28 and can prevent rotational displacement of the mounting jig 3 due to the moment My around the Y axis. If the displacement of A is small, one of the constant velocity joints may be fixed in the axial direction. Furthermore, both constant velocity joints are fixed in the axial direction, and in order to give the main body 30 of the connecting rod 29 a degree of freedom in the axial direction, a spline joint 40 as shown in FIG. may be formed.

Car body 1 was used as a sample in the above-mentioned place.
However, by modifying the mounting jig 3, it is also possible to perform vibration tests on various mechanical devices.

As mentioned above, by using the multi-axis vibrating device to which this invention is applied, vibration tests can be performed without creating unnecessary moments as noise on the specimen side, and the specimen can be subjected to vibration tests. There is no inconvenience caused by occasional damage.

[Brief explanation of the drawing]

Figure 1 is a schematic explanatory diagram of the vehicle body vibration test, Figure 2
, 3 and 4 are perspective views of main parts of different conventional multi-axis vibration exciters, and FIGS. An explanatory diagram of the operation of the vibration device, FIG. 9 is a perspective view of a multi-axis vibration device as an embodiment of this invention, and FIG. 10 is a side view of a connecting rod used in the multi-axis vibration device shown in FIG. 9. FIG. 11 is a schematic side view showing another embodiment of the main body of the above connecting rod. 1...Vehicle body, 3...Mounting jig, 14, 15...
Load bar, 16... Lateral load bar, 18,1
9... Lever, 20, 21, 38... Input device,
29... Connecting rod, 31, 32... Universal joint, 39
...Left-right lever, O...Load point, P...Input point.

Claims (1)

[Scope of utility model registration request] a specimen mounting jig that is removably fixed to the specimen, a pair of load bars whose upper ends are pivotally connected to the specimen mounting jig, and whose lower ends are arranged with their lower ends relatively spread; One end is pivoted to the sample mounting jig,
a left-right load bar whose other end is pivoted to a left-right lever that operates as a lever around the base by an input device;
It is equipped with a pair of longitudinal and vertical levers which are respectively pivotally connected to the lower ends of the pair of load bars and which are lever-operated around the base by the respective input devices, and the input devices apply arbitrary vibrations to the sample. In the multi-axis vibration excitation device configured to add a load, a universal joint is attached at both ends between the position on the specimen mounting jig where the load is applied by the specimen and the base, and the vibration excitation device is expandable and retractable in the axial direction. A multi-axis vibration device characterized by being connected by a connecting rod.