JP3446580B2 - Temperature detector for eddy current type reduction gear - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a temperature detection equipment which detects the temperature of the rotor of the eddy current type reduction gear which is mounted on a large vehicle, such as buses and trucks.

[0002]

2. Description of the Related Art As a braking device for an automobile, in addition to a foot brake which is a main brake and an exhaust brake which is an auxiliary brake, stable deceleration is performed when descending a long hill and the burn of the foot brake is prevented. Therefore, an eddy current type speed reducer (hereinafter referred to as "retarder") is used. This retarder includes one that uses an electromagnet as a magnet and one that uses a permanent magnet.

A retarder using an electromagnet has, as disclosed in, for example, Japanese Patent Application Laid-Open No. 50-61574, an electromagnet formed by winding a conductive wire around an iron electrode, and many of the electrodes are opposed to both sides of a disk. It is configured to be arranged. The deceleration force can be obtained by generating a magnetic field by energization from a battery power source and generating a desired torque in a direction of decelerating the disk by an eddy current generated in the disk.

The present applicants have used a permanent magnet instead of an electromagnet, and by changing the positions of the permanent magnet and the cylindrical member of the rotor, an eddy current is generated in the cylindrical member to decelerate the retarder. No. 234043, JP-A 1-234045, and JP-A 1-298948).

The structure of a retarder using a permanent magnet and the principle of generating a braking force will be described.

FIG. 2 is a diagram showing an example of a retarder using a permanent magnet, (a) is a cross-sectional view of a rotary shaft taken along a vertical line, and (b) is a cross-sectional view.
FIG. 4 is a plan view seen from the direction of the rotation axis. As shown in the figure, the retarder is composed of a rotor R fixed to the rotating shaft 1 and a stator S fixed to the transmission case 14.

The rotor R is composed of a flange 2, a wheel 3, a spoke 4, a cylindrical member 5 and a fin 6. The cylindrical member 5 is attached to the wheel 3 via the spoke 4, and one end (left side in FIG. 1A) is joined to the tip of the spoke 4 by welding, and one end of the spoke has a cushioning mechanism.
It is inserted in the wheel 3 via 4a. Wheel 3
It is bolted to flange 2. Flange 2
Is attached to the end of the rotary shaft 1 by a nut 13. A plurality of fins 6 are attached to the outer peripheral portion of the cylindrical member 5 in order to dissipate heat generated by the eddy current.
Further, a cushioning mechanism 4a composed of a "spring" or the like is incorporated between the spoke and the wheel so that the deformation due to the temperature rise can be absorbed.

The stator S has a frame body 10 for accommodating two ring-shaped yokes 8 and 8a having permanent magnets 7 and 7a fixed to their outer peripheral portions.
And the pole piece 9 at the position facing the outer circumference of the permanent magnet.
And a frame cover 11 in which is provided. Then, the transmission case 14 is inserted through the frame support tool 12.
Is attached to.

3A and 3B are diagrams schematically showing the arrangement of the permanent magnets. FIG. 3A is a diagram showing a braking off state, and FIG. 3B is a diagram showing a braking on state.

The permanent magnets 7, 7a are strip-shaped as shown in the figure, and are fixed at equal intervals to the outer peripheral portions of the ring-shaped yokes 8, 8a with different polarities on the surfaces adjacent to each other in the circumferential direction. There is. The yoke 8 can be oscillated in the circumferential direction by a driving device (not shown) as indicated by a double-headed arrow, and the yoke 8a is fixed to the frame body 10 (see FIG. 2). Then, as shown in FIG.
If the magnetic poles on the surfaces of the permanent magnet 7 and the permanent magnet 7a are arranged differently in the axial direction, the braking force does not work on the rotor, and if they are arranged in the same axial direction as shown in Fig. 3 (b), the braking force works on the rotor. become.

In the braking-on state, the rotor cylindrical member rotates across the magnetic field generated by the permanent magnet as shown by the single arrow in FIG. 2 (a), so that an eddy current flows in the cylindrical member 5 and this eddy current flows. Braking torque is generated in the rotor due to the interaction between the electric current and the magnetic field. The cylindrical member 5 is heated by the Joule heat associated with the eddy current, and is cooled and cooled by the cooling fin 6 in the braking off state.

In any of the methods, an eddy current is generated in the vicinity of the inner surface of the cylindrical member of the rotor due to the generation of the braking torque, and the temperature rises. In particular, in a rotor in which the inner surface of a cylindrical member is coated with a copper layer for the purpose of improving the generation of braking torque, heat generation further increases and the temperature of the stator also rises. When the temperature of the cylindrical member increases, the material strength of the cylindrical member decreases, and the copper layer deteriorates, which deteriorates the braking performance. In addition, the permanent magnet of the stator is
When exposed to high temperature, there is a risk of permanent demagnetization, and once permanent demagnetization occurs, the performance as a retarder cannot be exhibited. For this reason, a device has been proposed for the retarder in which the braking is turned off when the temperature of the cylindrical member of the rotor exceeds a predetermined temperature (for example, see Japanese Patent Laid-Open No. 4-217857).

A sheath type thermometer in which a wire type thermocouple or the like is inserted into a stainless steel protective tube is used for these temperature detectors. And Japanese Patent Laid-Open No. 4-21
In the temperature detecting device proposed in Japanese Patent No. 7857, an annular notch having a substantially rectangular cross section is provided at the end of the inner peripheral surface of the cylindrical member of the rotor, and a temperature detector that projects close to the annular notch is provided. However, the temperature of the cylindrical portion is detected from the ambient temperature of the annular cutout portion.

[0014]

In the above device, since the inner peripheral surface of the end portion of the cylindrical member is cut out in an annular shape, the braking force is reduced. Further, since the mounting position of the temperature detector is the end portion of the cylindrical member, the temperature is cooled by the air flow caused by the rotation of the rotor, and the detected temperature becomes low. When the detected temperature becomes low,
The ambient temperature (ambient temperature around the temperature detector) is easily affected by a change (seasonal change), and the predetermined temperature at which the braking is turned off is deviated.

If the braking is turned off when the temperature of the cylindrical member is lower than a predetermined temperature, the braking time cannot be shortened and the retarder ability cannot be sufficiently exhibited. On the contrary, if the braking is turned off at a temperature higher than the predetermined temperature, the cylindrical member and the stator may become hot, which may cause abnormality (deformation etc.) in the cylindrical member or demagnetize the permanent magnet.

An object of the present invention is not affected by the outside temperature, to provide a no temperature sensing equipment of lowering the braking performance of the retarder.

[0017]

SUMMARY OF THE INVENTION The means for solving the problem] is the temperature detection equipment below and as shown in FIG.

Frame 10 and frame that form the stator S
A part of the outer peripheral surface of the cover 11 is covered with a frame cover from the side of the frame 1.
Groove 16 is formed toward the side of the
The cylinder with the open end of the side surface 10-1 attached to the side surface of the frame body
It reaches the position of the member side surface 5-1 and is not in contact with the cylindrical member side surface.
Touch, such is covered by a hood 17, before through the hood of this
Make sure that the peripheral surface of the groove does not touch the bottom surface or both side surfaces of the groove.
Strangely An assembly as retarder sheath thermometer 15 is disposed.

The sheath type thermometer has a tip portion 15-1 of 5 m.
In the retarder described above, the area of m is blackened.
Temperature detection device .

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises (1) a stator
Groove formed in part of the outer peripheral surface of the frame and frame cover
The open end of the cylindrical member is attached to the side of the frame.
It is covered with a hood that reaches the stand and does not contact the side surface of the cylindrical member.
(2) It penetrates this hood and is not in contact with the groove.
This is a temperature detection device that consists of a sheathed thermometer that is attached in a touching state . (3) The temperature around the temperature detection unit is kept from flowing and the temperature of the temperature detection unit is raised to increase the influence of changes in the outside air temperature. To improve the accuracy of detecting the temperature of the cylindrical member forming the rotor. Each will be described below.

(1) A cylinder that constitutes the rotor with the open end of the groove
Regarding that the side surface of the member is covered with a hood: Fig. 1 is a diagram showing a temperature detecting device of the present invention, (a) is a longitudinal sectional view, and (b) is a plan view. This figure shows a state of being attached to the retarder. Fig. 2 (a) is an enlarged view of part A in Fig. 2 (a), and Fig. 2 (b) is an enlarged view of part B in Fig. 2 (b).

The temperature detecting device of the present invention is a sheath type thermometer.
15 is fixed to the center of the hood 17 by the set screw 18,
The tip portion 15-1 of the sheath type thermometer is the frame 10 of the stator and
The frame cover 11 has a structure in which it is inserted into a groove 16 provided in a part 11-2 of the outer peripheral surface of the frame cover 11 and covered by a hood.

The hood 17 is a side surface 5-of the cylindrical member of the rotor.
It is attached to the side surface 10-1 of the frame body 10 close to 1, and covers the side surface 5-1 of the cylindrical member and the open end of the groove 16 so that the atmosphere in the groove does not flow.

The sheath type thermometer 15 is a stator of the retarder.
In the groove 16 provided in part 11-2 of the outer peripheral surface of the frame body and the frame body cover , the temperature detecting portion is provided in the peripheral portion (side surface and bottom surface) of the groove.
Inserted without touching. For this reason, the temperature detection unit includes the inner surface of the cylindrical member 5, the frame 10 and the frame cover 11.
The temperature of the inner surface of the cylindrical member can be measured by inserting it into the atmosphere surrounded by the groove 16 provided on the outer peripheral surface and the side surface of the hood 17 and reducing the influence of the outside air as described later. In the present invention, the size of the groove is defined in relation to the temperature detecting section to increase the temperature of the temperature detecting section.

(2) Regarding the attachment mode of the sheath type thermometer: In the sheath type thermometer, the detection temperature varies depending on the attachment mode , and when the temperature of the temperature detecting part is low, the influence of the variation of the outside air temperature It was clarified in the following tests conducted by the inventors that they are susceptible to susceptibility.

As shown in FIG. 2, a retarder equipped with a temperature detecting device provided with a hood (for a braking torque of 40 kgf-m,
The outer diameter of the rotor fin is 455 mm and the width of the stator is 120.
mm) was prepared and a braking test was conducted under the conditions shown in Table 1.

[0027]

[Table 1]

In the braking test, the rotation speed of the rotor was set to 2200rp.
keeping the m and 3000 rpm, and the position of the permanent magnet to measure the temperature of the temperature and the cylindrical member end portion of the cylindrical member inner surface of the case of the maximum braking. The temperature of the cylindrical member inner surface, embedding a thermocouple into the cylindrical member widthwise center, was measured via a slip ring.
The detection temperature of the temperature of the cylindrical member inner surface reaches 650 ° C. were shown in Table 1.

A braking test was conducted by varying the size of the groove of the temperature detecting device, and the temperature of the inner surface of the cylindrical member and the temperature detected by the sheath type thermometer were measured.

FIG. 4 is a diagram for explaining the relationship between the sheath type thermometer and the groove. Set the diameter of the sheath thermometer to D (3.
2mm), the insertion length from the hood end of the sheath type thermometer is L
1, the groove length is L, the groove width is W, the distance between the outer circumference of the sheath thermometer and the groove side wall is d1, the distance from the tip of the sheath thermometer to the groove end is d2, and the stator frame body Width of H (70
mm).

In this test, one sheath-type thermometer was used, and a braking test was performed by changing the shape while cutting the groove, and the sheath-type temperature when the temperature of the inner surface of the cylindrical member reached 650 ° C. The temperature detected by the meter was measured. The results are shown in Table 2.

Specimens 1 to 7 are obtained by changing the insertion length L1 of the sheath type thermometer from 10 mm to 60 mm and making other conditions equal. The results are shown in Table 1 and FIG.

FIG. 5 is a diagram showing the relationship between the temperature detected by the sheath type thermometer and the insertion length of the sheath type thermometer when braking is applied from 3000 rpm. As can be seen from the figure, when the insertion length L1 is 25 mm, the temperature detected by the sheath thermometer (hereinafter, simply referred to as "detection temperature") shows the maximum value, and the insertion length is 20 to 30 mm. (1/2 of the width of the frame
A temperature of 100 ° C or higher can be detected in the range of (smaller than).

Specimens 8 to 15 are obtained by changing the distance d2 from the tip of the sheath-type thermometer to the groove end from 1 mm to 40 mm and making other conditions equal. In the test body 5, the distance d2 between the tip of the sheath thermometer and the groove end corresponds to 70 mm. The results are shown in Table 1 and FIG.

FIG. 6 is a diagram showing the relationship between the detected temperature when braking is applied from 3000 rpm and the distance from the tip of the sheath thermometer to the groove end. As is clear from the figure, when the distance d2 from the tip of the sheath-type thermometer to the groove end increases, the detected temperature decreases, but 5 mm is allowable. However, when d2 is 0 (zero, the sheath type thermometer is in contact with the groove end), the detected temperature is as low as 120 ° C.

The test bodies 16 to 20 are the same as the other conditions except that the distance d1 between the sheath type thermometer and the side wall of the groove is changed from 5 mm to 1 mm. In the test body 13, the distance d1 between the sheath type thermometer and the groove side wall corresponds to 6 mm. Those results
It shows in Table 1 and FIG.

FIG. 7 is a diagram showing the relationship between the detected temperature when braking is applied from 3000 rpm and the distance from the sheath type thermometer to the groove side wall. As is clear from the figure, when the distance d1 between the sheath type thermometer and the side wall of the groove increases, the detected temperature decreases, but up to 2 mm can be tolerated. However, when d1 is 0 (zero, the sheath thermometer is in contact with the side wall of the groove), the detected temperature is as low as 135 ° C.

Specimens 21 to 27 are obtained by changing the blackening length from 2 mm to 20 mm and making other conditions equal.
It should be noted that the test body 18 corresponds to the one that is not blackened. The results are shown in Table 1 and FIG.

FIG. 8 is a diagram showing the relationship between the detected temperature when braking is applied from 3000 rpm, the sheath type thermometer and the blackened length. As is clear from the figure, the blackened length may be 5 mm or more.

(3) About not letting the atmosphere around the temperature detecting section flow: The means for keeping the atmosphere around the temperature detecting section from flowing is as follows.
It is obtained by the sheath type thermometer having the above-mentioned hood and the manner of mounting the sheath type thermometer in the groove.

The test body 28 is for examining the presence or absence of a hood. Comparing the test body 28 with the test body 18, when the atmosphere temperature is 10 ° C. and the braking is applied from 2200 rpm, the hood increases the temperature from 218 ° C. to 255 ° C. (the difference is 37 ° C.). It rises to 235 ℃ (the difference is 37 ℃). On the other hand, when the ambient temperature rises to 40 ° C, the change due to the provision of the hood changes from 222 ° C to 254 ° C at 3000 rpm.
(The difference is 32 ° C), which is smaller than when the ambient temperature is 10 ° C. Further, the difference in the detected temperature due to the increase in the ambient temperature is 19 ° C with the hood, but is 24 ° C without the hood, which is larger than the case.

FIG. 9 is a diagram showing the influence of the hood on the detected temperature. As is clear from the figure, in any case, the detection temperature is higher when the hood is provided.

Specimens 29-31 have a preferred groove shape. Among them, the test body 31 is the best temperature detecting device provided with a hood and having a preferable groove shape.

FIG. 10 is a diagram showing the influence of the outside air temperature on the detected temperature. This figure shows an example of a test piece having different hoods and groove shapes from Table 1 . As is apparent from the figure, the increase in the detected temperature due to the increase in the outside temperature is smaller when the hood is provided. That is, it is shown that the influence of the change in the outside air temperature can be reduced by providing the hood. It also shows that the influence of changes in the outside air temperature can be reduced by optimizing the groove shape.

[0045]

Since the temperature detecting device of the present invention is provided with the hood covering the detecting portion, the flow of the atmosphere due to the rotation of the rotor and the running of the automobile is reduced, and the detection temperature of the sheath type thermometer is high, and the detection is performed. Time delay is reduced.
Since the retarder equipped with the temperature detecting device of the present invention can raise the set temperature for turning on and off the braking, the time for turning on the braking can be made longer than before. Also,
The temperature detection accuracy improves, and the life of the permanent magnet can be extended.

[Brief description of drawings]

1A and 1B are views showing a temperature detecting device of the present invention, in which FIG. 1A is a vertical sectional view and FIG. 1B is a plan view.

2A and 2B are views showing an example of a retarder using a permanent magnet, in which FIG. 2A is a sectional view taken along a longitudinal axis of a rotary shaft, and FIG. 2B is a plan view seen from the rotary shaft direction.

FIG. 3 is a diagram schematically showing the arrangement of permanent magnets, (a)
FIG. 4B is a diagram showing a braking off state, and FIG. 7B is a diagram showing a braking on state.

FIG. 4 is a diagram for explaining a relationship between a sheath type thermometer and a groove.

FIG. 5 is a diagram showing the relationship between the temperature detected by the sheath thermometer and the insertion length of the sheath thermometer when braking is applied from 3000 rpm.

FIG. 6 is a diagram showing the relationship between the detected temperature when braking is applied from 3000 rpm and the distance from the tip of the sheath thermometer to the groove end.

FIG. 7 is a diagram showing a relationship between a detected temperature when braking is applied from 3000 rpm and a distance from a sheath type thermometer to a groove side wall.

FIG. 8 is a diagram showing the relationship between the detected temperature when braking is applied from 3000 rpm, the sheath type thermometer, and the blackened length.

FIG. 9 is a diagram showing the influence of the hood on the detected temperature.

FIG. 10 is a diagram showing the influence of the outside air temperature on the detected temperature.

[Explanation of symbols]

1. Rotation axis 2. Flange 3. Wheel 4.
Spokes 4a. Buffer mechanism 5. The cylindrical member 6. Fin 7,7
a. Permanent magnet 8,8a. York 9. Pole piece 10. Frame 1
1. The frame body cover 12. Frame support 13. Nut 14. Transmission case 15. Sheath type thermometer 16. Groove 17. Hood 18.
Set screw

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-4-251600 (JP, A) JP-A-58-65920 (JP, A) Practical development Sho-59-112124 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H02K 49 / 02,49 / 10,11 / 00

Claims (2)

(57) [Claims] 1. A ring-shaped outer peripheral surface having a permanent magnet fixed thereto.
A yoke, a frame for housing the yoke, and the permanent magnet described above.
Frame cover with pole pieces arranged at the position facing the stone
And a stator with a specified gap.
Has a cooling fin on the outer peripheral surface that is rotatably fitted.
And a rotor with a cylindrical member
A temperature detecting device for a speed device, the frame constituting a stator
From the side of the frame to a part of the outer peripheral surface of the body and the frame cover
A groove is formed toward the side of the frame cover.
The circle in which the open end of the side surface of the frame is attached to the side surface of the frame
It reaches the position of the side surface of the cylindrical member and does not contact the side surface of the cylindrical member.
It is covered with a transparent hood, and penetrates this hood to
The peripheral surface does not contact the bottom surface and both side surfaces of the groove in the groove.
It is characterized in that a sheath type thermometer is arranged
Eddy current speed reducer temperature detector. 2. The sheath type thermometer has a tip of 5 mm.
The region according to claim 1, wherein the region is blackened.
Temperature detector for the mounted eddy current type speed reducer .