Sensor fixing tool and temperature detection device

Abstract

To reduce an influence which travel wind exerts on a detection value of a temperature by a temperature sensor.SOLUTION: A sensor fixing tool 5 is for mounting a temperature sensor 4 on a brake shoe 3 of a drum brake 2 of a vehicle and it includes: a sensor bracket 31 for fixing the temperature sensor 4; and a spring bracket 32 which has a constitution for pressing the temperature sensor 4 and the sensor bracket 31 to the surface of the brake shoe 3 by utilizing elastic force. The sensor bracket 31 includes: a sensor suppressing part 33 which has a constitution for generating suppressing force for installing the detection part 21 of the temperature sensor 4 at a temperature detection place on the surface of the brake shoe 3; a contact part 35 coming into contact with the surface of the brake shoe 3; a support pillar 39 having a constitution for holding the posture of the temperature sensor 4; and a sensor windshield 41 having a constitution for covering at least part of a portion excluding the portion opposing to the surface of the brake shoe 3 out of the tip of the detection part 21 of the temperature sensor 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sensor fixture for attaching a temperature sensor to a brake shoe of a drum brake of a vehicle, and a temperature detection device including the sensor fixture.

Background Art

[0002] In vehicles such as trucks, buses, and trailers, abnormal conditions such as heat generation of the brake shoe may occur due to brake dragging during driving with the brakes applied. Conventionally, as a countermeasure against such problems, there is an abnormality detection device that measures the temperature of the brake shoe or the like using a temperature sensor attached to the brake shoe of the drum brake, and detects the above abnormal conditions based on the degree of temperature rise, temperature difference, etc.

[0003] Patent Document 1 discloses a sensor fixture for attaching a temperature sensor to a brake shoe of a drum brake. The sensor fixture disclosed in Patent Document 1 has a configuration in which it is mounted so as to be sandwiched by elastic force on a plate-shaped rim portion to which a brake lining in the brake shoe is attached.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a conventional sensor fixture including the sensor fixture disclosed in Patent Document 1, the tip of the detection part of the temperature sensor is exposed. Further, there are drum brakes having a structure in which outside air easily flows into the inside thereof. Due to such circumstances, in the configuration of the conventional sensor fixture, when the running wind generated as the vehicle runs flows into the inside of the drum brake, the detected temperature value by the temperature sensor is affected by the running wind and changes, and there is a risk that the accuracy of temperature measurement decreases.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a sensor fixture and a temperature detection device capable of reducing the influence of running wind on the detected temperature value by a temperature sensor.

Means for Solving the Problems

[0007] The sensor fixture according to claim 1 is for attaching a temperature sensor (4) to a brake shoe (3) of a drum brake (2) of a vehicle, and includes a sensor bracket (31, 71) for fixing the temperature sensor, and a spring bracket (32) having a structure for pressing the temperature sensor and the sensor bracket against the surface of the brake shoe using an elastic force. The sensor bracket includes a sensor holding part (33) having a structure for generating a holding force for installing the detection part (21) of the temperature sensor at a temperature detection location on the surface of the brake shoe, a contact part (35) that contacts the surface of the brake shoe, a support column (39) having a structure for holding the posture of the temperature sensor, and a sensor wind guard (41, 72) having a structure for covering at least a part of a part of the tip of the detection part of the temperature sensor excluding a part facing the surface of the brake shoe.

[0008] According to the above configuration, since the temperature sensor and the sensor bracket are pressed against the surface of the brake shoe, accurate temperature measurement can be realized. Further, according to the above configuration, even when the running wind generated during the running of the vehicle flows into the inside of the drum brake, it is difficult for the running wind to directly hit the tip of the detection part of the temperature sensor, so that the detection value of the temperature by the temperature sensor is suppressed from fluctuating due to the influence of the running wind. Therefore, according to the above configuration, the influence of the running wind on the detection value of the temperature by the temperature sensor can be reduced, and as a result, an excellent effect that the accuracy of the temperature measurement is improved can be obtained.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0010] Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, substantially the same configurations are denoted by the same reference numerals and the description thereof will be omitted. (First Embodiment) Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 8.

[0011] <Overall Configuration> As shown in FIG. 1, the temperature detection device 1 of the present embodiment is provided on the brake shoe 3 of a drum brake 2 mounted on a vehicle such as a truck, a bus, and a trailer. The temperature detection device 1 includes a temperature sensor 4 and a sensor fixture 5 for attaching the temperature sensor 4 to the brake shoe 3. The sensor fixture 5 is configured to detachably mount the temperature sensor 4. The temperature detection device 1 is used to detect an abnormal state related to the brake, such as wear of the brake lining 6 and brake overheating, by detecting the temperature of the brake shoe 3.

[0012] <Configuration of Drum Brake> As shown in FIG. 2, the drum brake 2 to which the temperature detection device 1 is attached includes a brake drum 11, a brake shoe 3, a brake lining 6, an S cam 12, and a return spring 13. The brake shoe 3 has a rim portion 14 that is a shoe rim and a reinforcing portion 15 that is a shoe web. The rim portion 14 is a strip-shaped member that extends in the longitudinal direction with a predetermined width and thickness, that is, a long plate-shaped member, and is a member that is curved in an arc shape along the longitudinal direction. That is, the rim portion 14 is a strip-shaped plate member that curves and extends in the circumferential direction.

[0013] The reinforcing portion 15 is a member that protrudes perpendicularly to the rim portion 14 along the circumferential direction of the rim portion 14 from the concave surface of the rim portion 14, that is, the inner peripheral surface 14a on the side opposite to the brake lining 6. That is, the reinforcing portion 15 is a plate-shaped member formed along the circumferential direction of the rim portion 14 at the central portion in the width direction of the rim portion 14. The width direction of the rim portion 14 is the direction of the axle to which the drum brake 2 is attached.

[0014] The brake shoe 3 is configured such that its cross-sectional shape, that is, the cross-sectional shape cut along the axle, is T-shaped. Two brake shoes 3 are provided for one drum brake 2. The pair of brake shoes 3 are arranged such that the convex surface of the rim portion 14, that is, the outer peripheral surface 14b side, faces the inner peripheral wall 11a of the brake drum 11 with a certain gap, and one end of each is rotatably supported by the anchor pin 16. Hereinafter, in the brake shoe 3, the end opposite to the end supported by the anchor pin 16 will be referred to as the open end.

[0015] The brake lining 6 is attached to the brake shoe 3. Specifically, the brake lining 6 is attached to the outer peripheral surface 14b side, which is the convex surface of the rim portion 14. The brake lining 6 generates braking force by being pressed against the inner peripheral wall 11a of the brake drum 11 by the brake shoe 3. Two brake linings 6 are attached to each brake shoe 3.

[0016] In this case, the two brake linings 6 attached to the same brake shoe 3 are arranged separated by about several millimeters so that a gap 17 in which the brake shoe 3 is exposed is formed between them. As will be described later, the sensor fixture 5 is attached to the brake shoe 3 using the gap 17 between the pair of brake linings 6.

[0017] The S-cam 12 is an S-shaped member rotatably attached to contact the open ends of the pair of brake shoes 3 respectively. In the above configuration, when the brake pedal is depressed, the actuator 18 rotates the S-cam 12 in the direction of widening the space between the open ends of the pair of brake shoes 3, that is, in the direction of pressing the brake lining 6 against the brake drum 11. Thereby, braking is performed by the frictional force generated between the brake lining 6 and the rotating brake drum 11.

[0018] The return spring 13 is connected between the open ends of the pair of brake shoes 3. In the above configuration, when the depression of the brake pedal is released, the actuator 18 rotates the S cam 12 in a direction to narrow the space between the open ends of the pair of brake shoes 3. As a result, due to the biasing force of the return spring 13, the brake lining 6 is held at a position with a gap from the brake drum 11, and the braking is released.

[0019] <Configuration of the temperature detection device> As shown in FIGS. 1 and 3, the temperature detection device 1 includes a temperature sensor 4 and a sensor fixture 5. Note that at the position where the temperature detection device 1 is attached, the upper side in FIGS. 1 and 3 is the inner peripheral surface 14a side of the rim portion 14, that is, the axle side on the axis center side of the drum brake 2, and the lower side in FIGS. 1 and 3 is the outer peripheral surface 14b side of the rim portion 14.

[0020] The temperature sensor 4 detects the temperature of the brake shoe 3 of the drum brake 2 of the vehicle and is attached to the brake shoe 3 by the sensor fixture 5. The temperature sensor 4 is a rod-shaped member bent at two locations, and includes a linear detection portion 21 on one end side and a sensor extension portion 22 that bends from the inside of the detection portion 21 and extends to the other end side. The portion on one end side including the detection portion 21 of the temperature sensor 4 is actually covered by a partial configuration of the sensor fixture 5, but in FIGS. 1 and 3, it is shown transparently for convenience of explanation. A cylindrical connection portion 23 is connected to the other end of the temperature sensor 4, that is, the tip side of the sensor extension portion 22. A lead portion 24 is connected to the connection portion 23.

[0021] Among the temperature sensors 4, the detection unit 21 and the sensor extension unit 22 are covered with a metal cylindrical member, and the outer shape of its cross section is circular. The detection unit 21 has a temperature-sensitive part (not shown) inside, whose electrical characteristics change according to temperature. Specifically, the temperature sensor 4 includes a thermocouple composed of two different metal conductors, and the connection part of the thermocouple serves as the above-mentioned temperature-sensitive part. In the temperature sensor 4, the connection part of the thermocouple, which is the temperature-sensitive part, is located at the tip of the detection unit 21, that is, at one end of the temperature sensor 4. In other words, in the temperature sensor 4, the temperature-sensitive part is provided at the tip of the detection unit 21.

[0022] <Configuration of the Sensor Fixture> As shown in FIGS. 1 and 3, the sensor fixture 5 includes a sensor bracket 31 and a spring bracket 32. The sensor bracket 31 and the spring bracket 32 are separate members processed from a metal plate such as a stainless steel plate, respectively.

[0023] The sensor bracket 31 is arranged on the inner peripheral surface 14a side of the rim portion 14 and is a member for fixing the temperature sensor 4. That is, as will be described later, a part of the sensor bracket 31, specifically, a sensor holding portion 33 to be described later, is arranged so as to cover a part of the detection unit 21 of the temperature sensor 4, and is configured to press and fix the detection unit 21 toward the rim portion 14 by the elastic force of the spring bracket 32.

[0024] The spring bracket 32 fixes the detection unit 21 of the temperature sensor 4 by pressing a sensor holding portion 33, which is a part of the sensor bracket 31, with its own elastic force, and is a member that fixes the sensor fixture 5 itself to the rim portion 14 in a manner that sandwiches the rim portion 14, that is, detachably. In this way, the spring bracket 32 has a structure that presses the temperature sensor 4 and the sensor bracket 31 against the surface of the brake shoe 3 using elastic force.

[0025] As shown in FIGS. 4 to 7, the sensor bracket 31 is a jig that maintains the posture of the temperature sensor 4 and attaches the temperature sensor 4 to the brake shoe 3, and includes a base portion 34, a contact portion 35, a bracket holding portion 36, a pair of standing portions 37, a pair of protruding portions 38, a sensor holding portion 33, a support column 39, a sleeve holding portion 40, and a sensor windshield 41. The base portion 34 has a flat plate shape and is the central portion in FIG. 5.

[0026] The contact portion 35 has a flat plate shape. That is, the contact portion 35 is composed of a plate-like member in which no hole is formed. The contact portion 35 is provided on one end side of the base portion 34, specifically, the left side of the base portion 34 in FIG. 5. The contact portion 35 contacts the surface of the brake shoe 3, specifically, the inner peripheral surface 14a of the rim portion 14. In this way, the contact portion 35 is structured to receive the temperature of the surface of the brake shoe 3, which is a heating element, as much as possible to reduce the temperature difference between the temperature sensor 4 and the sensor bracket 31.

[0027] The bracket holding portion 36 is a part of the spring bracket 32, specifically, the portion directly pressed by the first extension portion 52. The bracket holding portion 36 is provided at one end of the base portion 34, specifically, the right side of the base portion 34 in FIG. 5. The pair of standing portions 37 are portions that regulate the movement of the spring bracket 32. The standing portions 37 are configured to extend upward with respect to the bracket holding portion 36 from one end of the bracket holding portion 36, specifically, the upper side of the bracket holding portion 36 in FIG. 5.

[0028] The pair of protrusions 38 are members for positioning the sensor bracket 31 with respect to the rim portion 14, that is, protrusions for locking the sensor bracket 31 to the rim portion 14. The protrusions 38 are configured to extend linearly from the left and right ends of the base portion 34 in FIG. 5 and then bend downward with respect to the base portion 34. As a result, the tip of the protrusion 38 protrudes downward with respect to the base portion 34. The rim portion 14 is provided with a plurality of through holes for fixing the brake lining 6, and rivets 42 are respectively arranged in each through hole. A recess is formed in the head of each rivet 42, and the tip of each protrusion 38 fits into the recess, so that the positioning and prevention of the sensor bracket 31 from falling off are configured.

[0029] The sensor holding portion 33 is a portion for fixing the detection portion 21 of the temperature sensor 4, and is provided at one end of the bracket holding portion 36, specifically, on the right side of the bracket holding portion 36 in FIG. 5. The sensor holding portion 33 has a fixed curved portion 33a. As shown in FIG. 3, the fixed curved portion 33a is curved so as to surround the upper part of the detection portion 21 and convex upward in FIG. 3, and is in a semi-cylindrical shape extending along the longitudinal direction of the detection portion 21, that is, the vertical direction in FIG. 5.

[0030] The sensor holding portion 33 presses the detection portion 21 of the temperature sensor 4 at the portion of the fixed curved portion 33a, and fixes the detection portion 21 between itself and the inner peripheral surface 14a of the rim portion 14. In this way, the sensor holding portion 33 has a structure for generating a holding force for installing the detection portion 21 of the temperature sensor 4 at the temperature detection location on the surface of the brake shoe 3.

[0031] As shown in FIGS. 4 and 7, etc., the support column 39 is a flat plate-shaped perforated support column with a central portion hollowed out. That is, the support column 39 is composed of a plate-shaped member in which a hole portion 39a is formed. In FIG. 7, only the support column 39 is shown, and the illustration of other configurations is omitted. The support column 39 is configured to extend obliquely upward with respect to the contact portion 35 from one end of the contact portion 35, specifically, the upper end of the contact portion 35 in FIG. 5. A sleeve holding portion 40 is provided at the upper end portion of the support column 39. The sleeve holding portion 40 has a mechanism for holding the sensor extension portion 22 and the connection portion 23 of the temperature sensor 4. Thus, the support column 39 has a structure for holding the posture of the temperature sensor 4.

[0032] The sensor windshield 41 is provided below the sensor holding portion 33 in FIG. 5 so as to be continuous with the sensor holding portion 33. The sensor windshield 41 has a fixed curved portion 41a. As shown in FIG. 6, the fixed curved portion 41a is curved so as to surround the upper part of the detection portion 21 and protrude upward in FIG. 6, and is in a semi-cylindrical shape extending along the longitudinal direction of the detection portion 21, that is, the vertical direction in FIG. 5, as shown in FIG. 3, etc. In FIG. 6, only the detection portion 21 and the sensor windshield 41 are shown, and the illustration of other configurations is omitted.

[0033] Thus, the sensor windshield 41 has a structure that covers at least a part of the portion of the tip of the detection portion 21 of the temperature sensor 4 excluding the portion facing the surface of the brake shoe 3. In this case, as shown in FIG. 6, a non-contact structure is formed between the tip of the detection portion 21 of the temperature sensor 4 and the sensor windshield 41. According to such a structure, a gap 43 is formed between the tip of the detection portion 21 and the sensor windshield 41, and thereby an air layer, which is an air layer, is provided between them.

[0034] As shown in FIGS. 1 and 3, the spring bracket 32 includes an elastic bending portion 51, a first extension portion 52, a second extension portion 53, an outer peripheral side locking portion 54, a connecting portion 55, a third extension portion 56, and a positioning portion 57. The elastic bending portion 51 is a portion where a plate material is bent into a substantially U shape so as to connect the first extension portion 52 and the second extension portion 53. When an external force that narrows the space between the first extension portion 52 and the second extension portion 53 is applied, the elastic bending portion 51 generates an elastic force that repels the external force.

[0035] The first extension portion 52 is a plate-like portion that extends from one end of the elastic bending portion 51, specifically, the lower end of the elastic bending portion 51 in FIG. 1 to the left side in FIG. 1, that is, the outer side when mounted on the rim portion 14. The second extension portion 53 is a plate-like portion that extends from the other end of the elastic bending portion 51, specifically, the upper end of the elastic bending portion 51 in FIG. 1 to the left side in FIG. 1. The first extension portion 52 is a portion that is arranged to contact the bracket holding portion 36 of the sensor bracket 31 and cover the bracket holding portion 36. The first extension portion 52 is arranged to cover the upper portion of the bracket holding portion 36, that is, the side opposite to the rim portion 14.

[0036] The outer peripheral side locking portion 54 is a strip-shaped plate material that is arranged in the gap 17 between the left and right brake linings 6 when the sensor fixture 5 is fixed to the rim portion 14. The outer peripheral side locking portion 54 is arranged perpendicular to the plane including the first extension portion 52, that is, perpendicular to the outer peripheral surface 14b of the rim portion 14. That is, the outer peripheral side locking portion 54 is arranged such that its width direction is perpendicular to the outer peripheral surface 14b and its thickness direction is in the circumferential direction of the outer peripheral surface 14b, that is, the width direction of the gap 17. The connecting portion 55 is a plate-like portion that connects the second extension portion 53 and the outer peripheral side locking portion 54.

[0037] The third extension part 56 is a plate-shaped part that extends in the circumferential direction of the outer peripheral surface 14b from one end of the connecting part 55. The positioning part 57 is a plate-shaped part that extends downward from the middle part of the third extension part 56. When the spring bracket 32 is pushed into the rim part 14, the positioning part 57 abuts against the outer side surface 14c of the rim part 14 to restrict, that is, position, the spring bracket 32 from being pushed in further.

[0038] <Mounting Method of Temperature Sensor> Next, an example of the mounting method for mounting the temperature sensor 4 to the brake shoe 3 by the sensor fixture 5 will be described. As shown in FIG. 1 and the like, first, the sensor bracket 31 is arranged on the inner peripheral surface 14a side of the rim part 14. Specifically, with the temperature sensor 4 held by the sensor bracket 31, that is, with the tip side of the sensor extension part 22 or the connection part 23 held by the sleeve holding part 40, the sensor bracket 31 is arranged on the inner peripheral surface 14a side of the rim part 14.

[0039] At this time, the detection part 21 is arranged below the sensor holding part 33 of the sensor bracket 31 and the fixed bending parts 33a, 41a of the sensor windshield 41, and the detection part 21 is sandwiched between the sensor holding part 33 and the rim part 14. Also, at this time, the pair of protrusion parts 38 of the sensor bracket 31 are fitted into the concave parts of the heads of the rivets 42. Thereby, the sensor bracket 31 is positioned.

[0040] Subsequently, with the sensor bracket 31 arranged as described above, the spring bracket 32 is attached to the rim part 14 by pressing the bracket holding part 36, which is a part of the sensor bracket 31. Specifically, the elastic bending part 51 of the spring bracket 32 is directed toward the inner side of the rim part 14. At this time, the outer peripheral side locking part 54 of the spring bracket 32 is arranged at the position of the gap 17 between the pair of brake linings 6.

[0041] At this time, the upper part of the bracket holding part 36 of the sensor bracket 31 is covered by the first extension part 52 of the spring bracket 32. Therefore, due to the elastic force of the elastic bending part 51, the first extension part 52 is pressed downward, and the bracket holding part 36 is pressed downward by the first extension part 52. Along with this, the sensor holding part 33, and thus the detection part 21, is pressed against the rim part 14 and fixed. In this way, due to the elastic force of the elastic bending part 51, the detection part 21 is fixed to the rim part 14, and at the same time, the sensor bracket 31 and the spring bracket 32 themselves are attached to the rim part 14. That is, the sensor fixture 5 itself is attached to the rim part 14, and the temperature sensor 4 is attached to the brake shoe 3.

[0042] According to the present embodiment described above, the following effects can be obtained. The sensor fixture 5 of the present embodiment is for attaching the temperature sensor 4 to the brake shoe 3 of the vehicle drum brake 2, and includes a sensor bracket 31 for fixing the temperature sensor 4, and a spring bracket 32 having a structure for pressing the temperature sensor 4 and the sensor bracket 31 against the surface of the brake shoe 3 using elastic force. The sensor bracket 31 includes a sensor holding part 33 having a structure for generating a holding force for installing the detection part 21 of the temperature sensor 4 at the temperature detection location on the surface of the brake shoe 3, a contact part 35 that contacts the surface of the brake shoe 3, a support column 39 having a structure for holding the posture of the temperature sensor 4, and a sensor windshield 41 having a structure for covering at least a part of the part of the tip of the detection part 21 of the temperature sensor 4 excluding the part facing the surface of the brake shoe 3.

[0043] According to the above configuration, since the temperature sensor 4 and the sensor bracket 31 are pressed against the surface of the brake shoe 3, accurate temperature measurement can be achieved. Further, according to the above configuration, even when running wind generated as the vehicle travels flows into the inside of the drum brake 2, it is difficult for the running wind to directly hit the tip of the detection unit 21 of the temperature sensor 4. Therefore, it is possible to suppress fluctuations in the temperature detection value by the temperature sensor 4 due to the influence of the running wind. Thus, according to the present embodiment, it is possible to reduce the influence of the running wind on the temperature detection value by the temperature sensor 4, and as a result, an excellent effect of improving the accuracy of temperature measurement can be obtained.

[0044] The effect obtained by such a present embodiment becomes even clearer by comparing it with a comparative example corresponding to a temperature detection device that employs a conventional sensor fixture in which the tip of the detection unit of the temperature sensor is exposed. In the comparative example, the same names and reference numerals will be given to the same configurations as those of the present embodiment for description. In the comparative example, the mechanism pattern of an event in which outside air such as running wind flowing into the inside of the drum brake 2 affects the detection unit 21 of the temperature sensor 4 will be described.

[0045] [1] First Pattern The first pattern is a pattern in which the inside air of the drum brake 2 cooled by the inflow of outside air affects the detection unit 21 of the temperature sensor 4 via the sensor bracket 31. The heat dissipation path in the first pattern is "brake shoe 3 (heating element)" → "temperature sensor 4" → "sensor bracket 31 (sensor suppressing part 33)" → "inside air of drum brake 2".

[0046] [2] Second Pattern The second pattern is a pattern in which the inside air of the drum brake 2 cooled by the inflow of outside air directly affects the detection unit 21 of the temperature sensor 4. The heat dissipation path in the second pattern is "brake shoe 3 (heating element)" → "tip of the detection unit 21 of the temperature sensor 4" → "inside air of drum brake 2".

[0047] In the comparative example, when outside air such as traveling wind flows into the inside of the drum brake 2, the detection unit 21 of the temperature sensor 4 is cooled by each heat dissipation path in the first pattern and the second pattern. As a result, the detected value of the temperature by the temperature sensor 4 becomes a value different from the original value, and there is a possibility that the accuracy of the temperature measurement may decrease. On the other hand, in the present embodiment, since the sensor wind guard 41 is provided, there is no path for heat transfer directly from the tip of the detection unit 21 of the temperature sensor 4 to the inside air of the drum brake 2.

[0048] That is, in the present embodiment, the structure is such that outside air such as traveling wind does not directly hit the tip of the detection unit 21 of the temperature sensor 4. Therefore, according to the present embodiment, as compared with the comparative example, the detection unit 21 of the temperature sensor 4 is not cooled by the path for heat transfer directly from the tip of the detection unit 21 to the inside air of the drum brake 2, and accordingly, the influence of the traveling wind on the detected value of the temperature by the temperature sensor 4 is reduced.

[0049] Further, in the present embodiment, the structure between the tip of the detection unit 21 of the temperature sensor 4 and the sensor wind guard 41 is non-contact. In order to improve the force for pressing the detection unit 21 of the temperature sensor 4 against the surface of the brake shoe 3, it is also conceivable to adopt a structure in which the tip of the detection unit 21 of the temperature sensor 4 and the sensor wind guard 41 are brought into contact to hold the entire detection unit 21. However, in such a contact structure, a path similar to the heat dissipation path in the first pattern of the comparative example is formed, and the tip of the detection unit 21 is cooled through that path.

[0050] On the other hand, according to the non-contact structure as in the present embodiment, an air layer is provided between the sensor bracket 31 and the temperature sensor 4, and the thermal resistivity between them is improved. In this way, although a heat dissipation path of "brake shoe 3" → "tip of the detection unit 21 of the temperature sensor 4" → "gap 43 (air layer)" → "sensor wind guard 41" → "inside air of the drum brake 2" is formed, since the thermal resistivity of the gap 43 is high, it is difficult for the tip of the detection unit 21 to be cooled through this path, and thus the influence of the traveling wind on the detected value of the temperature by the temperature sensor 4 is further reduced.

[0051] Further, in the present embodiment, the support column 39 is constituted by a plate-shaped member in which a hole portion 39a is formed. According to this, the area of the support column 39, which is a part of the sensor bracket 31 affected by outside air such as traveling wind, can be suppressed to be small. According to such a configuration, since the decrease in the temperature of the support column 39 due to the influence of outside air is suppressed, the temperature difference between the sensor bracket 31 and the temperature sensor 4 is reduced, so that the heat dissipation amount of the heat dissipation path from the temperature sensor 4 to the sensor bracket 31 is reduced. Therefore, according to the above configuration, the influence of the traveling wind on the temperature detection value by the temperature sensor 4 can be further reduced.

[0052] Further, in the present embodiment, the contact portion 35 is constituted by a plate-shaped member in which no hole portion is formed. According to this, the area of the contact portion 35, which is a part of the sensor bracket 31 that comes into contact with the brake shoe 3 which is a heating element, can be increased. According to such a configuration, since the temperature difference between the sensor bracket 31 and the temperature sensor 4 is reduced, the heat dissipation amount of the heat dissipation path from the temperature sensor 4 to the sensor bracket 31 is reduced. Therefore, according to the above configuration, the influence of the traveling wind on the temperature detection value by the temperature sensor 4 can be further reduced.

[0053] As described above, according to the present embodiment, the influence of the traveling wind on the temperature detection value by the temperature sensor 4 can be reduced compared to the comparative example. Specifically, as shown in FIG. 8, in the comparative example, the fluctuation of the temperature detection value was about 0.15°C at maximum, but in the present embodiment, the fluctuation of the temperature detection value is suppressed to about 0.1°C at maximum. That is, according to the present embodiment, compared to the comparative example, at maximum, the influence of the traveling wind on the temperature detection value by the temperature sensor 7 can be reduced by about 30%. In FIG. 8, the vertical axis represents "the slope [°C / s] of the brake temperature in a predetermined period", and the horizontal axis represents "time [s]".

[0054] (Second Embodiment) Hereinafter, the second embodiment will be described with reference to FIG. 9. As shown in Fig. 9, the sensor bracket of this embodiment is different from the sensor bracket 31 of the first embodiment in that a heat transfer prevention member 61 is added. The heat transfer prevention member 61 is provided so as to be interposed between the tip of the detection unit 21 of the temperature sensor 4 and the sensor windshield 41, and is a member having a lower thermal conductivity than air. Specifically, for example, a resin seal or the like can be used as the heat transfer prevention member 61. When a resin seal is used as the heat transfer prevention member 61, the seal can be attached to one or both of the inner peripheral surface of the fixed curved portion 41a of the sensor windshield 41 and the fixed curved portion 33a of the sensor holder 33.

[0055] According to the present embodiment described above, compared with the case where only an air layer is provided between the tip of the detection unit 21 of the temperature sensor 4 and the sensor bracket 31, the thermal conductivity between the tip of the detection unit 21 of the temperature sensor 4 and the sensor bracket 31 can be reduced. Therefore, according to the present embodiment, although a heat dissipation path of "brake shoe 3" → "tip of the detection unit 21 of the temperature sensor 4" → "gap 43 (air layer)" → "heat transfer prevention member 61" → "sensor windshield 41" → "inner air of the drum brake 2" is formed, since the thermal conductivity of the heat transfer prevention member 61 is smaller than that of air, the tip of the detection unit 21 is more difficult to be cooled through this path, and thus the influence of the traveling wind on the temperature detection value by the temperature sensor 4 is further reduced.

[0056] (Third Embodiment) Hereinafter, the third embodiment will be described with reference to Fig. 10. As shown in Fig. 10, the sensor bracket 71 of this embodiment is different from the sensor bracket 31 of the first embodiment in that it is provided with a sensor windshield 72 instead of the sensor windshield 41. The sensor windshield 72 includes a fixed curved portion 72a similar to the fixed curved portion 41a of the sensor windshield 41, and further includes a semi-circular lid portion 72b provided so as to cover the opening of the fixed curved portion 72a. In this way, the sensor windshield 72 has a structure that covers all of the portion of the tip of the detection unit 21 of the temperature sensor 4 except the portion facing the surface of the brake shoe 3.

[0057] According to the present embodiment described above, since the traveling wind is less likely to hit the tip of the detection unit 21 of the temperature sensor 4, the detected temperature value by the temperature sensor 4 is further suppressed from fluctuating due to the influence of the traveling wind. Further, according to the above configuration, the air layer, i.e., the gap 43, is less likely to cool due to the influence of the traveling wind, and the effect of receiving the temperature of the surface of the brake shoe 3 is also enhanced, so that more accurate temperature measurement can be realized.

[0058] (Other Embodiments) Note that the present invention is not limited to the embodiments described above and shown in the drawings, and can be arbitrarily modified, combined, or extended without departing from the gist thereof. The numerical values and the like shown in the above embodiments are merely examples and are not limited thereto. The support column 39 may be constituted by a plate-like member in which two or more holes are formed. The heat transfer prevention member 61 is not limited to a resin seal, and may be realized, for example, by filling the gap 43 with a resin having a lower thermal conductivity than air.

[0059] This disclosure has been described based on the embodiments, but it is understood that this disclosure is not limited to the embodiments and structures. This disclosure includes various modifications and modifications within the equivalent scope. In addition, various combinations and forms, and further, other combinations and forms including only one element, more, or less thereof among them, fall within the scope and spirit of this disclosure.

Description of Reference Numerals

[0060] 1... Temperature detection device, 2... Drum brake, 3... Brake shoe, 4... Temperature sensor, 5... Sensor fixture, 21... Detection unit, 31, 71... Sensor bracket, 32... Spring bracket, 33... Sensor suppressor, 35... Contact part, 39... Support column, 39a... Hole, 41, 72... Sensor wind guard, 61... Heat transfer prevention member.

Claims

1. A sensor fixture for attaching a temperature sensor (4) to a brake shoe (3) of a drum brake (2) of a vehicle, comprising: a sensor bracket (31, 71) for fixing the temperature sensor; a spring bracket (32) having a structure for pressing the temperature sensor and the sensor bracket against the surface of the brake shoe using an elastic force; and comprising: The sensor bracket includes: a sensor holding part (33) having a structure for generating a holding force for installing a detection part (21) of the temperature sensor at a temperature detection location on the surface of the brake shoe; a contact part (35) that contacts the surface of the brake shoe; a support (39) having a structure for holding the posture of the temperature sensor; and a sensor windshield (41, 72) having a structure for covering at least a part of a portion of the tip of the detection part of the temperature sensor excluding a portion facing the surface of the brake shoe; A sensor fixture.

2. The sensor fixture according to claim 1, wherein a non-contact structure is formed between the tip of the detection part of the temperature sensor and the sensor windshield.

3. The sensor fixture according to claim 1, wherein the support is constituted by a plate-like member in which at least one hole (39a) is formed.

4. The sensor fixture according to claim 1, wherein the contact part is constituted by a plate-like member in which no hole is formed.

5. Furthermore, the sensor fixture according to claim 1, further comprising a heat transfer prevention member (61) having a lower thermal conductivity than air, provided so as to be interposed between the tip of the detection part of the temperature sensor and the sensor windshield.

6. The sensor fixture according to claim 1, wherein the sensor windshield (72) has a structure for covering the entire portion of the tip of the detection part of the temperature sensor excluding a portion facing the surface of the brake shoe.

7. A temperature sensor (4) for detecting the temperature of a brake shoe (3) of a drum brake (2) of a vehicle; and a sensor fixture (5) according to any one of claims 1 to 6. A temperature detection device comprising the same.

Images