JPS6118969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a testing machine for testing the durability against torsional torque of a differential gear device of an automobile or the like.

Various methods have been considered to perform this type of test, but in order to efficiently utilize the input power, power circulation torsion testing machines have traditionally been used in which the output is fed back into the input. .

By the way, a differential gear device has two output shafts for one input shaft, and both output shafts are rotated according to the rotation of the input shaft, but the rotation speed of each output shaft depends on the rotation speed of the input shaft. is not limited, only the total number of rotations of both output shafts is limited. Therefore, in the case of a durability test of a differential gear device, it is necessary to perform the test while varying the rotational speed difference between the two output shafts. However, in the case of a power circulation type, the power appearing on both output shafts is returned to the input shaft, but the problem is how to combine the powers of the two output shafts, which have different rotational speeds.

As such a test device, there is a conventional test device as shown in FIG. This power circulation type torsion testing machine 10 controls the rotation of the drive motor 11 by gears 12 and 13.
The transmission is transmitted to the hydraulic motor 14 and the input shaft 16 of the differential gear device 15 as a test sample, and also to the left and right output shafts 17, 18 of the differential gear device 15.
Hydraulic pumps 19 and 20 are attached to both hydraulic pumps 19 and 20, and hydraulic pressure from the hydraulic motor 14 is supplied to both hydraulic pumps 19 and 20, and the hydraulic pressure on the discharge side of both hydraulic pumps 19 and 20 is returned to the hydraulic motor 14. There is. A torque detector 21 is provided on the output shaft 22 of the hydraulic motor 14, and its detection signal is amplified by an amplifier 23 and added to the specified torque voltage addition point 25 as a negative feedback signal. The specified torque voltage is amplified by an amplifier 24 to control a servo valve 26 of the hydraulic motor 14. The hydraulic motor 14 continuously changes its swash plate angle (tilt angle) using an attached servo valve 26, thereby reducing the output flow rate when the swash plate angle is small and reducing the output flow rate when the swash plate angle is large. The output flow rate is controlled to increase when .

Now, the hydraulic motor 14 is driven by the drive motor 11 at a rotation speed equal to the rotation speed transmitted to the input shaft of the differential gear device 15 as a test sample. Both output shafts 1 of the differential gear device 15
7 and 18 drive respective hydraulic pumps 19 and 20, so those hydraulic pumps 19 and 20 are
The hydraulic pressure is output to the input side of the hydraulic motor 14. As a result, if the swash plate angle of the hydraulic motor 14 is made small by the servo valve 26, the input side of the hydraulic motor becomes high pressure, and the hydraulic pumps 19, 20 become a large load on the output shafts 17, 18. Therefore, a large torsional torque is generated in the differential gear 15. This torsional torque is then applied to the output shaft 22
It is detected by the torque detector 21 at the position of , and is maintained at a predetermined value by negative feedback control so that the torsional torque becomes a predetermined value.

Although not shown, a means for applying a rotational speed difference to both output shafts 17 and 18 is provided, and the test is performed by varying the rotational speed difference to various values.

As mentioned above, the conventional power circulation type torsional durability testing machine has a hydraulic pump installed on both output shafts, which discharges an amount of oil according to the rotation speed, and by merging each oil, the power of both output shafts can be adjusted. It synthesizes.

However, this method has the disadvantage that the advantages of the power circulation system cannot be fully demonstrated due to the poor power transmission efficiency of the hydraulic circuits such as the hydraulic pump and the hydraulic motor.

The present invention was developed to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a durability testing machine for a differential gear device with improved power transmission efficiency.

The durability testing machine according to the present invention, which was created to achieve this purpose, uses two differential gear devices as test samples, and connects the left and right output shafts of these devices via gears, and also connects the left and right output shafts of these devices via gears. The rotational speed of the three axes n 1 _, n ₂ , n ₃ of the axes is such that the relationship n ₁ - n ₂ = n ₃ holds true between the first and third axes of the differential gear device separate from the test sample. A power circulation loop is formed by connecting two shafts via two shafts, and power is supplied to the power circulation loop from the outside, and a torque generating means is coupled to a third shaft of the separate differential gear, and the torque generating means is connected to a third shaft of the separate differential gear. It is characterized in that the generating means is feedback-controlled by a signal from a torque detector provided in the power circulation loop.

As described above, the gears were connected using two differential gear units as test samples and a differential gear unit separate from the test sample that interconnects the input shafts of the two differential gear units. A power circulation loop is formed, and the third shaft of the separate differential gear device is used to apply torque to the loop, so it is not possible to use a conventional hydraulic circuit using a hydraulic motor or the like. In comparison, the efficiency can be greatly improved.

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings.

As shown in FIG. 2, the differential gear device durability tester 30 of the present invention includes two differential gear devices 31 and 32 as test samples, a drive device 33, and a torque generator 34 as main parts. and a rotation control device 35.

The two differential gear devices 31, 32 are arranged symmetrically on a plane, and have output shafts 36, 37, 3, respectively.
8, 39 are gears 41,
It is connected to 42, 43, and 44. The gears 41, 42, 43, and 44 each have the same number of teeth and mesh with each other.

The drive device 33 includes the differential gear devices 31 and 32.
The rotation of the motor shaft 47 of the drive motor 80 is transmitted to the connecting shaft 52 via the flange joint 51 by the bevel gear 48, and to the other connecting shaft 53 by the bevel gear 49. The rotation of one connecting shaft 52 is coupled to the input shaft 45 of one differential gear device 31 by the universal joint 54, and the rotation of the other connecting shaft 53 is coupled to the input shaft 45 of the differential gear device 55 by the bevel gear 50. The other differential gear device 3
It is connected to the input shaft 46 of No. 2.

Further, the torque generating device 34 is connected to the drive device 33.
It is interposed in the transmission path of the closed loop transmission path and generates a predetermined torque in the transmission path, and a differential gear device 55 is provided between the connecting shafts 53 and 58. Differential gear device 55
A hydraulic motor 62 is attached to the control shaft 61 of
is operated by the control servo valve 63, and
The rotational torque of the output shaft 56 is detected by a torque detector 65, and the detected signal is amplified by an amplifier 66 and then negatively fed back to an addition point 67, thereby controlling the torque to be maintained at a predetermined value. The hydraulic motor 62 receives the control hydraulic pressure Ps as an input, and can freely manipulate the swash plate angle by the output of the servo valve 63, thereby making it possible to arbitrarily change the rotation as the output.

The rotation control device 35, for example, adjusts the rotation of a pair of output shafts 38, 39 of the differential gear device 32, and detects the rotation speeds of both output shafts 38, 39 with detectors 68, 69. Detector 68,6
9 are amplified by amplifiers 70 and 71, respectively, and added to the rotation difference designation signal at an addition point 72 with the sign shown in the figure.The added signal is amplified by an amplifier 73, and this signal is used to control a motor 74. The rotation is transmitted to one gear 43 by gear 75.

Next, the operation will be explained. The rotation of the motor shaft 47 of the drive motor 80 is transmitted as a rotational speed N ₁ to the input shaft 45 of one differential gear device 31 via the bevel gear 48, the flange shaft joint 51, the connecting shaft 52, and the universal joint 54. Ru. Therefore, the rotation speed N ₁ of the input shaft 45 of the differential gear device 31 is
Normally, the speed is reduced by the rotation ratio of the differential gear device 31, and an average rotation speed is applied to the output shafts 36 and 37, respectively.
Transmitted as _N2 . On the other hand, the rotation of the motor shaft 47 of the drive motor 80 is transmitted through the bevel gear 49, the connecting shaft 53, the bevel gear 50, the output shaft 56, the output shafts 56, 57 of the differential gear device 55, the connecting shaft 58, and the universal joint 59. The rotational speed N ₁ is also transmitted to the input shaft of the other differential gear device 32 . Here too, the rotation speed N ₁ of the input shaft 46 of the differential gear device 32 is
The rotational speed _N2 is transmitted to the output shafts 38 and 39 based on the same rotational ratio. Here, the output shafts 36, 38, 37 of the two differential gear devices 31, 32,
The rotation ratio of 39 is the same. Therefore, the input shafts 45 and 46 of both differential gear devices 31 and 32 are
Each is in a state where it can rotate smoothly at the same number of rotations N ₁ . A power circulation loop is formed by the above.

However, the differential gear device 31, 3 as a test sample
The two output shafts 36, 38, 37, and 39 may have different mechanical resistances. In this case, one output shaft 36, 38 and the other output shaft 3
The rotation speeds of 7 and 39 will be different. Therefore, the rotation of one output shaft 36, 38 is detected by a rotation speed detector 68, and the rotation of the other output shaft 37, 38 is detected by a rotation speed detector 68.
The rotational speed of 39 is detected by a detector 69.
The respective detection signals are transmitted to amplifiers 70 and 71.
and is applied to the addition point 72 of the difference designation signal. For example, if both detection signals are equal,
The input to the amplifier 73 is only the rotation difference designation signal. This rotation difference designation signal is intended to provide the same conditions as the actual usage situation, and if there is a large rotation difference, it is adjusted based on the detection signals from the detectors 68 and 69, and is amplified by the amplifier 73. motor 74
to drive. For this reason, two differential gear devices 31,
32, a pair of left and right output shafts 36, 37, 38, 39
will rotate based on the same rotation or a predetermined rotation difference, respectively, in response to zero or a certain value of the rotation difference designation signal. In this way 2
Output shafts 36, 3 of differential gear devices 31, 32
If a deviation occurs in the target rotational difference between the rotational speeds 8, 37, and 39, the rotation control device 35 automatically detects the deviation and operates to always match the target rotational difference.

On the other hand, the differential gear device 55 is configured to have the ability to transmit sufficiently larger power than the differential gear devices 31 and 32 as samples,
It is placed under the control of a servo hydraulic motor 62 which is controlled by a torque designation signal.

The differential gear device 55 is a fifth differential gear device having the same configuration as the differential gear devices 31 and 32 as test samples.
The one shown in the figure is used. Now, for example, the shafts 56, 57, 61 of the differential gear device 55 correspond to the shafts 45, 36, 37 of the differential gear device 31, respectively.
Let the rotational speed of gear 5 be n ₁ , n ₂ , n ₃ respectively, and gear 5
Gear ratio of 5a and 55b is 1:2, gear 55c,
Gear ratio of 55d, 55e, 55f is 1:1:1:
1, and when the number of rotations of the gear 55b is n ₁ ', the relationship is n ₂ + n ₃ = 2n ₁ ', n ₁ = 2n ₁ ' n ₂ + n ₃ = n ₁ n ₁ − n ₂ = n ₃ . It works. Here, if the rotation speed of the shaft n ₃ is set to zero, n ₁ =n ₂ , and the rotation speeds of the shafts 56 and 57 are the same. Therefore, when the shaft 56 of the differential gear device 55 is rotated by the motor 80 via the shaft 47, bevel gears 49, 50, and shaft 56 at a rotational speed _N1 , the shaft 57 is also rotated at the same rotational speed _N1 . The gear tooth shaft devices 31, 32,
55 constitutes a power circulation loop by connecting as shown.

In this state, if the shaft 61 is rotated by an angle θ (phase), torque will be generated between the output shafts 56 and 57. Since the drive device 33 forms a closed loop transmission path with the motor shaft 47, connection shafts 52, 53, 58, and output shafts 56, 57, the above torque is always generated in any rotating part. There will be. Therefore, the two differential gear devices 31 and 32 rotate in the closed transmission path of the drive device 23 with constant torque applied thereto. Of course, this torque can be set to an appropriate desired value by increasing or decreasing the torque designation signal. Furthermore, if the torque designation signal is not a constant value but is input as a signal with a certain frequency that oscillates over time, both differential gear devices 31, 3
2, a dynamic repeated torsion torque is constantly applied, making it possible to reproduce conditions even closer to actual usage conditions.

Next, FIGS. 3 and 4 show other embodiments. Two differential gear devices 31 of this embodiment,
32 are combined in a vertical relationship. Further, the drive motor 79 of the drive device 33 is directly coupled to one output shaft 39 by a flange shaft joint 40. Therefore, in this embodiment, the bevel gears 48, 49, 50 and the connecting shafts 52, 5 of the previous embodiment are used.
3, 58, etc. can be omitted. In this way, the drive motor 79 only needs to finally drive the output shafts 36, 37, 38, 39 of the differential gear devices 31, 32, and can be placed at any position. Further, the torque generating device 34 is provided between the input shafts 45 and 46 of the two differential gear devices 31 and 32, and connects the input shafts 45 and 46 to reduction gears (missions).
A constant torsional torque is applied to the input shafts 45, 46 of the differential gear devices 31, 32 via the input shafts 76, 77. Further, the differential gear device 55 is driven by a swing motor 78.
The swing motor 78 rotates within a swing angle range of ±θ, and is composed of an electro-hydraulic rotary actuator. The swing motor 78 detects torque by the torque detector 65 of the output shaft 57, similarly to the servo valve 63 of the embodiment described above, and arbitrarily changes the rotation angle θ according to the detected torque. Further, the control motor 74 has left and right output shafts 36, 38, 3
7 and 39, and the torque is sufficient to correspond to the mechanical unbalanced torque that occurs between the left and right output shafts 36, 38, 37, and 39. A few tenths of the torque is sufficient. Further, the power of the drive motor 79 is high in energy efficiency because it is necessary to replenish only the energy lost in the rotating part including the sample.
Furthermore, the torque of the swing motor 78 must be large, but since its swing angle θ is sufficient with a small rotation angle, the flow rate of oil for driving the swing motor 78 is a small flow rate. Therefore, the swing motor 78 can be operated with very little power. In this embodiment, attention is paid to the fact that the output shafts 56 and 57 are parallel to each other on the same side, and correspondingly, the differential gear devices 31 and 32 are arranged in two stages, upper and lower. In this way, the drive device 33
The configuration can be simplified because it does not require many connecting shafts 52, 53, and 58.

To summarize above, in the testing machine according to the present invention, the pair of differential gear devices 31 and 32 as test samples are in a relationship in which they interlock with each other at the same rotation ratio at the output shafts 36, 38, 37, and 39. , even when the rotation ratio between the input and output of the differential gear devices 31, 32 changes, both the differential gear devices 31, 3
Since the rotations of the two input shafts 45 and 46 are always constant, the gear ratio of the entire drive system can be configured to always be constant.

In addition, the left and right output shafts 3 of the differential gear devices 31 and 32
The rotation of 6, 38, 37, 39 is controlled by the rotation control device 35.
Since the settings can be made arbitrarily, conditions close to actual usage conditions can be reproduced.

Furthermore, a torque generating device 34 is located in the transmission path of the drive device and can generate a static torsion torque and a dynamic torsion torque that changes periodically by electrical control.

As described above, according to the present invention, since the entire circulation system of the power transmission path is composed of gears, there is less energy loss and the efficiency of power transmission is improved compared to the conventional hydraulic drive system.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the configuration of a conventional durability testing machine for a differential gear device, FIG. 2 is a plan view of the configuration of a durability testing machine for a differential gear device of the present invention, and FIG. 3 is a plan view of the configuration of a durability testing machine for a differential gear device of the present invention. FIG. 4 is a left side view of the configuration of the embodiment, FIG. 4 is a left side view of the configuration of FIG. 3, and FIG. FIG. 30...Durability test machine for differential gear device, 31,3
2... Differential gear device, 33... Drive device, 34...
...torque generator, 35...rotation control device, 3
6, 37, 38, 39...output shaft, 41, 42,
43, 44... Gear, 45, 46... Input shaft, 8
0...Drive motor.

Claims (1)

[Claims] 1 In a test machine that tests the durability against torsional torque in which the difference in rotational speed between the left and right output shafts of a differential gear device is varied and set to a predetermined value, two differential gear devices were used as test samples. The left and right output shafts of the device are connected via gears, respectively, and the input shaft also has the rotational speed of the first to third axes n ₁ , n ₂ , n ₃
A power circulation loop is formed by connecting the test sample through the first and second shafts of a separate differential gear device with a relationship n ₁ −n ₂ =n ₃ between them, and forming a power circulation loop. A torque generating means is coupled to the third shaft of the separate differential gear, and the torque generating means is feedback-controlled by a signal from a torque detector provided in the power circulation loop. A durability testing machine for differential gears, which is characterized by the following: