TW202001117A - Drum brake device - Google Patents

Abstract

The present invention relates to a drum brake device, comprising a brake disk, a first brake shoe, a second brake shoe, at least one spring and a brake arm. One end of the brake disk is provided with a brake cam and the other end is provided with a pin having a pin groove. Wherein, a first arc stand is provided with a first rib that can contact the bottom of the pin groove, and a second arc stand is provided with a second rib that can contact the bottom of the pin groove, so that the first arc stand and the second arc stand form a containing space for filling the lubricant respectively with the bottom of the pin groove. As such, the lubricant can effectively eliminate the rubbing noise at the rotation of the pin groove, can maintain the practicality of the lubricant after a long period of use, and is not prone to the situation of lubricant outflow or heat drying to eliminate the abnormal sound phenomenon.

Description

Drum brake

The invention relates to a drum brake device, in particular to a drum brake device suitable for a locomotive brake system.

Please refer to FIG. 1, which is a conventional locomotive brake configuration diagram. As shown in the figure, the conventional brake system mainly includes a brake disc 91, a hub 92, a brake arm 93, and a brake cam 94, and is connected to the brake arm 93 through a brake wire 902 through a brake lever 901, so that The occupant can control the braking action of the entire vehicle via the brake lever 901.

Next, please refer to FIGS. 2 to 4, which are A-A cross-sectional view of FIG. 1, a partial view of FIG. 2, and a B-direction view of FIG. 3, respectively. The figure shows a conventional drum brake device, which includes a brake disc 91, a brake cam 94, a first brake shoe 95, a second brake shoe 96, two springs 97, and a brake arm 93. The first brake shoe 95 and the second brake shoe 96 are half-moon shaped bodies facing each other. One end of the first brake shoe 95 is provided with a first curved seat 951, and the other end is embedded with a first gasket 952; At one end of the second brake shoe 96, a second curved seat 961 is provided, and at the other end, a second gasket 962 is embedded. The brake cam 94 is disposed at one end of the brake disk 91, and includes a shaft portion 941 and a cam portion 942 provided with a cam groove portion 943. The shaft portion 941 passes through the brake disk 91 and engages the brake arm 93 at one end. When the brake arm 93 When actuated by force, the shaft portion 941 will also produce an interlocking relationship, causing the cam portion 942 to push against the first gasket 952 and the second gasket 962 accommodated in the cam groove portion 943. The other end of the brake disc 91 is provided with a pin body 98 having a pin body groove portion 981, which can be used to accommodate the first arc surface seat 951 and the second arc surface seat 961. In addition, two springs 97 are provided between the first brake shoe 95 and the second brake shoe 96, so that the first arcuate seat 951 and the second arcuate seat 961 can be simultaneously positioned on the pin body 98 of the brake disc 91, Used to provide the restoring force required when the two brake shoes 95, 96 are reset.

Please refer to FIGS. 5 and 6 together, which are partial views of FIG. 3 and side views of the conventional first brake shoe and second brake shoe, respectively. As shown, the first brake shoe 95 on the first curved seat 951 of width D1 and the second brake shoe 96 on the second curved seat 961 of width D2 are both installed on the pin body groove 981 of width D3 At the same time, the first pad 952 embedded in the first brake shoe 95 and the second pad 962 embedded in the second brake shoe 96 can also be positioned on the cam groove 943 of the brake cam 94 at the same time. In the above structure, the first arcuate seat 951 and the second arcuate seat 961 are in direct contact with the pin body groove portion 981, however, when the drum brake mechanism is actuated, the deflection caused by the manufacturing tolerance of the hub 92 may be The following problems occur.

Please refer to FIGS. 7 to 10, which are the state diagram after the actuation of FIG. 4, the state diagram after the hub of FIG. 7 is turned 90 degrees, the state diagram of the hub of FIG. 8 after turned 90 degrees, and the wheel hub of FIG. 9 State diagram after turning 90 degrees. As shown in FIG. 7, when the brake cam 94 rotates, the cam portion 942 will expand the first pad 952 of the first brake shoe 95 and the second pad 962 of the second brake shoe 96 at this time. The shoe 95 and the second brake shoe 96 rotate around the pin body 98, so that the material 953 of the first brake shoe 95 and the material 963 of the second brake shoe 96 can contact the hub 92 The annular friction surface 921 generates braking force.

However, due to manufacturing tolerances, when the hub 92 rotates at different angles, the gap between the first brake shoe 95 and the second brake shoe 96 will change. When the brake is actuated, the annular friction surface 921 of the hub 92 It can come into contact with the first brake shoe 95 and the second brake shoe 96 to produce a braking force, but the manufacturing tolerance of the hub 92 will make the annular friction surface 921 have a friction surface closest to the axis 9211 when the axis rotates. The furthest point between the friction surface and the axis is 9212. Since the closest point of the friction surface and the axis center 9211 and the farthest point of the friction surface and the axis center 9212 rotate with the hub 92, the force of the first brake shoe 95 and the second brake shoe 96 during light braking will follow the hub At different rotation angles of 92, the first brake shoe 95 and the second brake shoe 96 continue to reciprocate around the pin body 98. Due to this rotation phenomenon, the hub 92 causes the first brake shoe 95 and the second brake The intermittent force of the shoe 96 causes the pin body groove portion 981 to rotate to stimulate friction noise. Even if adding high temperature resistant butter or molybdenum disulfide to the friction surface of the pin body 98 can eliminate the noise, but with the hub 92 To make the wood dust sticky, when the high temperature resistant butter or molybdenum disulfide dry, the abnormal sound phenomenon will continue to occur and generate market complaints.

Because of this, the inventor, in the spirit of active invention, is anxious to think of a drum brake device that can solve the above-mentioned problems. After several studies and experiments, the present invention has been completed.

The main purpose of the present invention is to provide a drum brake device. By the arrangement of the ribs of the brake shoe, or by the arrangement of the ribs of the pin body of the brake disc, the arc surface seat and the bottom of the groove part of the pin body are formed It can be used to fill the accommodating space of lubricant. The lubricant can effectively eliminate the friction noise at the rotation of the groove of the pin body. It can still maintain the practicality of the lubricant after long-term use, and it is not easy for the lubricant to flow out or dry up due to heat. The situation, so that the abnormal sound phenomenon no longer occurs.

To achieve the above object, the drum brake device of the present invention includes a brake disc, a first brake shoe, a second brake shoe, at least one spring, and a brake arm. A brake cam is penetrated at one end of the brake disc, which includes a shaft portion and a cam portion having a cam groove portion, and the other end is provided with a pin body having a pin body groove portion.

Wherein, the first brake shoe is provided with a first curved seat at one end, and a first gasket is embedded at the other end. The first curved seat is placed in the groove of the pin body, and a first rib is provided to contact the bottom of the groove of the pin body So that a first accommodating space for filling lubricant is formed between the first arcuate seat and the bottom of the groove portion of the pin body, the first gasket is placed in the cam groove portion; in contrast, one end of the second brake shoe is provided There is a second curved surface seat, and a second gasket is embedded at the other end. The second curved surface seat is placed in the groove of the pin body, and a second rib is provided to contact the bottom of the groove of the pin body, so that the second curved surface seat and the pin A second accommodating space for lubricant filling is formed between the bottoms of the body grooves, and the second gasket is inserted into the cam grooves.

In addition, at least one spring is disposed between the first brake shoe and the second brake shoe, so that the first brake shoe and the second brake shoe are arranged on the pin body groove portion and the cam groove portion relative to each other. The brake arm is arranged at one end of the shaft part, and can transmit the applied force to rotate the brake cam.

Through the above design, the present invention effectively improves the deflection caused by the manufacturing tolerance of the hub in the conventional technology, and the difference between the gap formed between the annular friction surface of the hub and the second brake shoe is caused by the change of the second brake shoe. The frictional noise when the plate revolves around the pin body, through the improvement of the mechanical structure, the lubricant is effectively maintained in the accommodating space of the groove of the pin body, so as to achieve long-term lubrication and eliminate the generation of abnormal noise.

The width of the first rib may be less than one third of the width of the first arcuate seat. In this way, the surface pressure of the first brake shoe applied to the pin body can be increased three times, so as to reduce the chance of abnormal sound generated by the rotation of the first brake shoe on the pin body.

The width of the second rib may be less than one third of the width of the second arcuate seat. In this way, the surface pressure of the second brake shoe applied to the pin body can be increased three times, so as to reduce the chance of abnormal sound generated by the second brake shoe rotating the pin body.

Furthermore, in addition to the above structural features, the present invention can change the installation position of the ribs to form another drum brake device, which includes a brake disc, a first brake shoe, and a second brake shoe. At least one spring and one brake arm. One end of the brake disc is provided with a brake cam, which includes a shaft portion and a cam portion with a cam groove portion, and the other end is provided with a pin body, which has a pin body groove portion, in which the pin body groove portion is provided with a Contrary pin ribs.

One end of the first brake shoe is provided with a first arcuate seat, and the other end is embedded with a first gasket. The first arcuate seat is placed in the groove of the pin body, and the first arcuate seat is in contact with the pin body rib, so that the first A first accommodating space for filling lubricant is formed between a camber seat and the bottom of the groove portion of the pin body, the first gasket is placed in the cam groove portion; oppositely, a second The arc surface seat is embedded with a second gasket at the other end. The second arc surface seat is placed in the groove portion of the pin body, and the second arc surface seat contacts the pin body rib so that the second arc surface seat and the bottom of the pin body groove portion A second accommodating space for filling lubricant is formed therebetween, and the second gasket is placed in the cam groove portion.

In addition, at least one spring is disposed between the first brake shoe and the second brake shoe, so that the first brake shoe and the second brake shoe are arranged on the pin body groove portion and the cam groove portion relative to each other. The brake arm is arranged at one end of the shaft part, and can transmit the applied force to rotate the brake cam.

The groove portion of the pin body may be provided with two partition plates, so that the lubricant can be retained in the first accommodating space and the second accommodating space for a long time. Thereby, the partition plate is a stop structure, which effectively blocks the outflow path of the lubricant, so that the pin body can be kept in a lubricated state for a long time.

The two partitions may be O-rings. In addition to the function of retaining the lubricant in the first accommodating space and the second accommodating space for a long period of time, it can simultaneously achieve the function of shock absorption and reduce the first brake shoe The opportunity to directly hit the groove of the pin body with the second brake shoe.

The above summary and the following detailed description are of exemplary nature to further illustrate the patent application scope of the present invention. The other objects and advantages of the present invention will be explained in the following description and illustration.

Please refer to FIGS. 11 to 14, which are a cross-sectional view of the drum brake device according to the first embodiment of the present invention, a C-direction view of FIG. 11, a partial view of FIG. 11, and the first and second brake shoes. Side view. The figure shows a drum brake device, which mainly includes a brake disc 1, a brake cam 4, a first brake shoe 5, a second brake shoe 6, a second spring 7, and a brake arm 3.

In this embodiment, the first brake shoe 5 and the second brake shoe 6 are half-moon-shaped bodies facing each other. One end of the first brake shoe 5 is provided with a first curved seat 51, and the other end is embedded with a first In contrast, the second brake shoe 6 is provided with a second curved seat 61 at one end and a second gasket 62 embedded at the other end. The brake cam 4 is disposed at one end of the brake disk 1 and includes a shaft portion 41 and a cam portion 42 provided with a cam groove portion 43. The shaft portion 41 passes through the brake disk 1 and engages the brake arm 3 at one end. When the brake arm 3 When actuated by force, the shaft portion 41 will also produce an interlocking relationship, causing the cam portion 42 to push against the first gasket 52 and the second gasket 62 accommodated in the cam groove portion 43, so that the first brake shoe 5 The incoming material 53 and the incoming material 63 of the second brake shoe 6 can contact the annular friction surface of the hub to generate a braking force. The other end of the brake disc 1 is provided with a pin body 8 having a pin body groove portion 81, which can be used for accommodating the first arc surface seat 51 and the second arc surface seat 61. In addition, two springs 7 are provided between the first brake shoe 5 and the second brake shoe 6 to provide the restoring force required when the two brake shoes 5, 6 are reset.

Wherein, the width of the first arc-shaped seat 51 is W1, the ends of the arc-shaped seat 511 are provided at both ends, and a first rib 512 with a width of W4 is provided in the first arc-shaped seat 51, and according to the laboratory It is better to know that the width W4 should not be greater than one third of the width W1; relatively, the width of the second arcuate seat 61 is W2, and the arcuate seat end 611 is provided at both ends, and the second arcuate seat 61 There is a second rib 612 with a width W5, and according to experiments, the width W5 should not be greater than one third of the width W2. In this way, the present invention can increase the surface pressure of the second brake shoes 5, 6 applied to the pin body 8 three times, so as to reduce the chance of abnormal sound generated by the second brake shoes 5, 6 rotating the pin body 8.

Next, please refer to FIG. 15 together, which is a partially enlarged view of FIG. 11. As shown in the figure, the first brake shoe 5 and the second brake shoe 6 are installed on the pin body groove portion 81 and the cam groove portion 43 relative to each other, that is, the first brake shoe 5 is the first in the width W1 The arcuate seat 51 and the second brake shoe 6 in the width W2 of the second arcuate seat 61 will be installed in the pin body groove portion 81, and the first brake shoe 5 in the first arcuate seat 51 uses the first The rib 512 is in contact with the pin body 8, so there is a first accommodating space (not shown) between the first arcuate seat 51 and the bottom of the pin body groove portion 81, which can be filled with high temperature resistant grease or molybdenum disulfide lubricant; In contrast, the second brake shoe 6 uses the second rib 612 to contact the pin body 8 in the second arcuate seat 61, so there is a second between the second arcuate seat 61 and the bottom of the pin body groove 81 The accommodating space 613 can be filled with lubricants such as high temperature resistant butter or molybdenum disulfide. At this time, the first rib 512 and the second rib 612 will be surrounded by lubricants such as high temperature resistant butter or molybdenum disulfide around the contact with the pin body groove 81 Surrounded by it, the lubricant can provide lubrication between the first rib 512 and the second rib 612 and the pin body 8 at any time. At the same time, the complete coating function of the lubricant can prevent the leakage of residual abnormal sound.

Through the above design, the present invention effectively improves the deflection caused by the manufacturing tolerances of the hub described in the conventional technology, resulting in the formation of the annular friction surface of the hub and the two brake shoes with different gap changes caused by the second brake shoes The friction noise when reciprocating around the pin body, through the improvement of the mechanical structure, effectively maintains the lubricant in the accommodating space of the groove portion of the pin body, so as to achieve lubrication and eliminate the generation of abnormal noise.

Next, please refer to FIGS. 16 to 18, which are a cross-sectional view of a drum brake device according to a second embodiment of the present invention, a partial view of FIG. 16, and side views of a first brake shoe and a second brake shoe, respectively. The figure shows a drum brake device, which mainly includes a brake disc 1a, a brake cam 4, a first brake shoe 5a, a second brake shoe 6a, two springs 7, and a brake arm 3.

In this embodiment, the first brake shoe 5a and the second brake shoe 6a are half-moon shaped bodies facing each other. One end of the first brake shoe 5a is provided with a first curved seat 51, and the other end is embedded in a first In contrast, the second brake shoe 6a is provided with a second curved seat 61 at one end, and a second gasket 62 is embedded at the other end. The brake cam 4 is disposed at one end of the brake disk 1a, and includes a shaft portion 41 and a cam portion 42 provided with a cam groove portion 43. The shaft portion 41 passes through the brake disk 1a and engages the brake arm 3 at one end. When the brake arm 3 When actuated by force, the shaft portion 41 will also produce an interlocking relationship, causing the cam portion 42 to push against the first shim 52 and the second shim 62 accommodated in the cam groove portion 43, so that the first brake shoe 5a The incoming material 53 and the incoming material 63 of the second brake shoe 6a can contact the annular friction surface of the hub to generate a braking force. The other end of the brake disc 1a is provided with a pin body 8 having a pin body groove portion 81, wherein the pin body groove portion 81 is provided with a pin body rib 82 that can resist. In addition, two springs 7 are provided between the first brake shoe 5a and the second brake shoe 6a to provide the restoring force required when the two brake shoes 5a, 6a are reset.

Wherein, the width of the first arcuate seat 51 is W1, and the arcuate seat ends 511 are provided at both ends; in contrast, the width of the second arcuate seat 61 is W2, and the arcuate seat ends are provided at both ends部611. The width of the pin body groove portion 81 is W3, the width of the pin body rib 82 located in the pin body groove portion 81 is W6, and according to experiments, the width W6 of the pin body rib 82 is not greater than that of the first arc surface seat 51 One-third of the width W1 is better; relatively, the width W6 of the pin rib 82 is also not greater than one-third of the width W2 of the second arcuate seat 61. In this way, the present invention can increase the surface pressure of the second brake shoes 5a, 6a applied to the pin body 8 three times, so as to reduce the chance of abnormal sound generated by the second brake shoes 5a, 6a rotating the pin body 8.

Next, please refer to FIG. 19 together, which is a partially enlarged view of FIG. 16. As shown in the figure, the first brake shoe 5a and the second brake shoe 6a are installed on the pin body groove portion 81 and the cam groove portion 43 relative to each other, that is, the first brake shoe 5a is at the first width W1 The arcuate seat 51 and the second brake shoe 6a in the width W2 of the second arcuate seat 61 will be installed in the pin body groove 81, and the first arc shoe 51a of the first brake shoe 5a is connected to the pin body The ribs 82 are in contact, so there is a first accommodating space (not shown) between the first arc-shaped seat 51 and the bottom of the pin body groove portion 81, which can be filled with lubricants such as high temperature resistant butter or molybdenum disulfide; The second brake shoe 6a is also in contact with the pin body rib 82 in the second arcuate seat 61, so there is a second accommodating space 613 between the second arcuate seat 61 and the bottom of the pin body groove 81 to be filled Lubricants such as high-temperature butter or molybdenum disulfide, the pin body rib 82 will be completely surrounded by lubricants such as high-temperature butter or molybdenum disulfide in contact with the first arcuate seat 51 and the second arcuate seat 61, Lubricant can not only provide lubrication between the pin body rib 82 and the pin body 8 and the first arcuate seat 51 and the second arcuate seat 61 at any time, at the same time, through the complete coating function of the lubricant, it can avoid the leakage of residual abnormal sound.

Furthermore, please refer to FIG. 20 and FIG. 21, which are a cross-sectional view of a drum brake device according to a third embodiment of the present invention and a partially enlarged view of FIG. 20, respectively. As shown in the figure, the basic structure of this embodiment is the same as that of the second embodiment, which mainly includes a brake disc 1b, a brake cam 4, a first brake shoe (not shown), and a second brake shoe 6b , Two springs 7 and one brake arm 3. The pin body groove portion 81 of the brake disc 1b is provided with a pin body rib 82 that can resist, so that there is a first accommodating space between the first arc surface seat 51 and the bottom of the pin body groove portion 81, and the second arc There is a second accommodating space between the face seat 61 and the bottom of the pin body groove portion 81 to fill with lubricants such as high temperature resistant butter or molybdenum disulfide, the only difference is that this embodiment is further on the pin body groove portion 81 Two partition plates 83 are provided, and the two partition plates 83 are elastic O-rings, except that the lubricant can be kept in the first accommodating space and the second accommodating space 613 for a long time, avoiding being used as lubricant After drying up, the abnormal sound phenomenon of the pin body groove portion 81 occurs again, which can simultaneously achieve the function of shock absorption, reducing the chance that the first brake shoe 5b and the second brake shoe 6b directly hit the pin body groove portion 81.

The above embodiments are only examples for the convenience of description, and the scope of rights claimed by the present invention should be subject to the scope of the patent application, and not limited to the above embodiments.

1,1a,1b‧Brake disc 3‧‧‧Brake arm 4‧‧‧Brake cam 41‧‧‧Shaft part 42‧‧‧Cam part 43‧‧‧Cam groove part 5,5a‧‧‧First brake Hoof piece 51‧‧‧ First curved seat 511‧‧‧ End of curved seat 512‧‧‧ First rib 52‧‧‧ First gasket 53‧‧‧Ring material 6,6a,6b‧‧‧‧ Second brake shoe 61‧‧‧Second curved seat 611‧‧‧End of curved seat 612‧‧‧Second rib 613‧‧‧Second accommodating space 62‧‧‧Second gasket 63‧‧ ‧Lingling material 7‧‧‧Spring 8‧‧‧Pin body 81‧‧‧Pin body groove part 82‧‧‧Pin body rib 83‧‧‧Baffle 901‧‧‧Brake lever 902‧‧‧Brake wire 91‧ ‧‧Brake disk 92‧‧‧Hub 921‧‧‧Annular friction surface 9211‧‧‧The closest point 9212‧‧‧The farthest point 93‧‧‧Brake arm 94‧‧‧Brake cam 941‧‧‧Shaft part 942‧ ‧‧Cam part 943‧‧‧Cam groove part 95‧‧‧ First brake shoe 951‧‧‧First arc surface seat 952‧‧‧First gasket 953‧‧‧Ling material 96‧‧‧Second Brake shoe 961‧‧‧Second arc seat 962‧‧‧Second gasket 963‧‧‧Ring material 97‧‧‧Spring 98‧‧‧Pin body 981‧‧‧Pin body groove W1-W6‧ ‧‧Width D1-D3‧‧‧Width

Figure 1 is a conventional locomotive brake configuration diagram. FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. FIG. 3 is a partial view of FIG. 2. FIG. 4 is a view in the direction B of FIG. 3. FIG. 5 is a partial view of FIG. 3. FIG. 6 is a side view of conventionally known first brake shoes and second brake shoes. FIG. 7 is a state diagram of FIG. 4 after actuation. FIG. 8 is a state diagram of the hub of FIG. 7 rotated 90 degrees forward. FIG. 9 is a state diagram of the hub of FIG. 8 after being turned 90 degrees forward. FIG. 10 is a state diagram of the hub of FIG. 9 after being turned 90 degrees forward. 11 is a cross-sectional view of the drum brake device according to the first embodiment of the present invention. FIG. 12 is a view in the direction C of FIG. 11. FIG. 13 is a partial view of FIG. 11. 14 is a side view of the first brake shoe and the second brake shoe of the first embodiment of the present invention. 15 is a partial enlarged view of FIG. 11. 16 is a cross-sectional view of a drum brake device according to a second embodiment of the invention. FIG. 17 is a partial view of FIG. 16. 18 is a side view of the first brake shoe and the second brake shoe of the second embodiment of the present invention. Fig. 19 is a partially enlarged view of Fig. 16. 20 is a cross-sectional view of a drum brake device according to a third embodiment of the invention. 21 is a partially enlarged view of FIG. 20.

1‧‧‧brake disc

6‧‧‧Second brake shoe

61‧‧‧Second arc surface seat

611‧‧‧Curved seat end

612‧‧‧The second rib

613‧‧‧Second accommodating space

7‧‧‧Spring

8‧‧‧pin body

81‧‧‧Pin body groove

Claims (8)

A drum brake device includes: a brake disc, a brake cam is penetrated at one end, which includes a shaft portion and a cam portion having a cam groove portion, and the other end is provided with a pin body having a pin body groove portion; A first brake shoe with a first arcuate seat at one end and a first washer embedded at the other end, the first arcuate seat is placed in the groove of the pin body, and a A first rib, so that a first accommodating space for filling lubricant is formed between the first arc-shaped seat and the bottom of the groove portion of the pin body, the first gasket is inserted into the cam groove portion; a second brake The hoof piece is provided with a second arcuate seat at one end and a second gasket embedded at the other end. The second arcuate seat is inserted into the groove of the pin body and is provided with a second rib that touches the bottom of the groove of the pin body. A second accommodating space that can be filled with lubricant is formed between the second arcuate seat and the bottom of the groove portion of the pin body, the second gasket is placed in the cam groove portion; at least one spring is disposed on the first A brake shoe and the second brake shoe are arranged so that the first brake shoe and the second brake shoe are opposite to each other on the pin body groove and the cam groove; and a brake arm is provided At one end of the shaft portion, a force can be transmitted to rotate the brake cam. For example, the drum brake device according to item 1 of the patent application, wherein the width of the first rib is less than one third of the width of the first arc seat. For example, the drum brake device according to item 1 of the patent application, wherein the width of the second rib is less than one third of the width of the second arc seat. A drum brake device includes: a brake disc, a brake cam penetrating at one end, which includes a shaft portion and a cam portion having a cam groove portion, and a pin body at the other end having a pin body groove portion, Wherein, a groove of the pin body is provided with a pin rib that can be resisted; a first brake shoe with a first arc surface seat at one end and a first gasket embedded at the other end, the first arc surface seat is Inserted into the groove of the pin body and contacting the rib of the pin body with the first arc surface seat, so that a first accommodating space for filling lubricant is formed between the first arc surface seat and the bottom of the groove portion of the pin body , The first washer is inserted into the cam groove; a second brake shoe with a second curved seat at one end and a second washer embedded at the other end, the second curved seat is inserted into the pin In the body groove portion, the second arc surface seat is in contact with the pin body rib, so that a second accommodating space for filling lubricant is formed between the second arc surface seat and the bottom of the pin body groove portion, the second A washer is inserted into the cam groove; at least one spring is disposed between the first brake shoe and the second brake shoe, so that the first brake shoe and the second brake shoe are opposite to each other The pin body groove portion and the cam groove portion; and a brake arm, which is provided at one end of the shaft portion, can transmit an applied force to rotate the brake cam. For example, the drum brake device according to item 1 or item 4 of the patent application, wherein the groove part of the pin body is provided with two partition plates, so that the lubricant can be retained in the first accommodating space and the second accommodating space for a long time In the space. For example, the drum brake device according to item 5 of the patent application, wherein the two partition plates are O-rings, which have the function of shock absorption. For example, the drum brake device according to item 4 of the patent application, wherein the width of the pin body rib is less than one third of the width of the first arc seat. For example, the drum brake device according to item 4 of the patent application, wherein the width of the pin body rib is less than one third of the width of the second arc seat.

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