Reservoir tank and hydraulic brake device

Abstract

Provided is a reservoir tank for storing brake fluid to be supplied to a master cylinder attached to a vehicle, the reservoir tank comprising a passage chamber having a primary port and a secondary port, and a storage chamber that communicates with the passage chamber and that is provided farther forward in the vehicle than the primary port and the secondary port, wherein air entrained in the brake fluid within the reservoir tank is not drawn into the master cylinder. The passage chamber has a primary passage, which is a passage connecting the storage chamber and the primary port, and a secondary passage, which is a passage connecting the storage chamber and the secondary port, and partway along the primary passage and / or the secondary passage is a trap structure for capturing air generated in the brake fluid.

Description

【0001】 【Document Name】Specification 【0002】 【Title of the Invention】Reservoir Tank and Hydraulic Brake Device 【0003】 【Technical Field】 【0004】 【.001】The present invention relates to a reservoir tank for storing brake fluid and a hydraulic brake device equipped with the reservoir tank. 【0005】 【Background Art】 【0006】 【.002】Conventionally, in vehicles such as automobiles, there are vehicles that employ a hydraulic brake device that utilizes hydraulic pressure. In this hydraulic brake device, a reservoir tank for storing brake fluid supplied to a master cylinder that generates hydraulic pressure is used. 【0007】 【〇003】The reservoir tank is connected to the booster via the master cylinder. Also, the reservoir tank and the booster are arranged in the engine room. 【0008】 【〇004】Here, in the engine room of the vehicle, various components (adjacent components) are arranged adjacent to the reservoir tank in the vicinity of the reservoir tank. In Patent Document 1, an example in which adjacent components such as a harness are arranged above the reservoir tank is described. In order to avoid contact with this adjacent component, a reservoir tank in which a liquid storage portion (a portion including the supply port 14 in Patent Document 1) is arranged at a position shifted forward in the vehicle from the master cylinder is disclosed. 【0009】 【Prior Art Documents】 【0010】 【Patent Documents】 【0011】 【〇005】 【0012】 【Patent Document 1】Japanese Unexamined Patent Application Publication No. 2020 - 157900 【0013】 【Summary of the Invention】 【0014】 【Problems to be Solved by the Invention】 【0015】 [〇 0 0 6] Such reservoir tanks may carry the risk of drawing air into the brake fluid. If this drawn-in air is drawn into the master cylinder, it will be difficult for the brake pressure to rise. 【0016】 [〇 0 0 7] The present invention has been made in view of the above problems, and the object of the present invention is to provide a reservoir tank in which the storage chamber (liquid reservoir) is located in a position shifted forward of the vehicle from the master cylinder, in which air is drawn into the brake fluid in the reservoir tank, but the drawn-in air is not drawn into the master cylinder. 【0017】 [Means for solving the problem] 【0018】 [〇 0 0 8] The reservoir tank (2) according to the present invention is a reservoir tank (2) for storing brake fluid to be supplied to a master cylinder (5〇) attached to a vehicle, wherein the reservoir tank (2) has a passage chamber (4) having a primary port (21) and a secondary port (22), and a storage chamber (3) that communicates with the passage chamber (4) and is provided in a forward direction of the vehicle beyond the primary port (21) and the secondary port (22), wherein the passage chamber (4) has a primary passage (23) which is a passage connecting the storage chamber (3) and the primary port (21), and a secondary passage (24) which is a passage connecting the storage chamber (3) and the secondary port (22), and the primary passage (2 3) and / or a reservoir tank (2) located in the middle of the secondary passage (24) having a trap structure for capturing air drawn into the brake fluid. 【0019】 [Effects of the Invention] 【0020】[0 0 0 9] According to the present invention, in a reservoir tank where the storage chamber is positioned shifted forward of the vehicle from the master cylinder, it is possible to provide a reservoir tank in which, even if air is drawn into the brake fluid within the reservoir tank, the drawn-in air is not drawn into the master cylinder. 【0021】 [Brief explanation of the drawing] 【0022】 [ 0 0 1 0 ] 【0023】 [Figure 1] This is a schematic diagram of a hydraulic brake device according to an embodiment of the present invention. 【0024】 [Figure 2] This is a schematic diagram of the lower part of a reservoir tank according to an embodiment of the present invention. 【0025】 [Figure 3] This is a schematic diagram of the upper part of a reservoir tank according to an embodiment of the present invention. 【0026】 [Figure 4] This is a cross-sectional view of a reservoir tank according to an embodiment of the present invention. 【0027】 [Figure 5] This is a cross-sectional view illustrating a reservoir tank according to an embodiment of the present invention. 【0028】 [Figure 6] This is a schematic diagram illustrating the effects of a reservoir tank according to an embodiment of the present invention. 【0029】 [Figure 7] This is a schematic diagram illustrating the effects of a reservoir tank according to an embodiment of the present invention. 【0030】 [Modes for carrying out the invention] 【0031】 [0 0 1 1] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be omitted. 【0032】 [ 0 0 1 2 ] 【0033】(Hydraulic Brake System) Figure 1 is a schematic diagram showing an example of the configuration of a hydraulic brake system. The hydraulic brake system 1 in Figure 1 is an example of a hydraulic brake system in which the reservoir tank 2 according to the present invention is incorporated into a conventionally known master cylinder. 【0034】 [0 0 1 3] The hydraulic brake system 1 is a brake system in which brake fluid is used as the hydraulic fluid, and comprises a brake pedal 8, a multiplier device 9, a master cylinder 50 having a primary fluid chamber 52 and a secondary fluid chamber 54, a reservoir tank 2, and a wheel cylinder 6. 【0035】 [ 0 0 1 4 ] The primary fluid chamber 5 2 of the master cylinder 5〇 is connected to the primary port 2 1 of the reservoir tank 2 (described later), and the secondary fluid chamber 5 4 is connected to the secondary port 2 2 of the reservoir tank 2 (described later). Brake fluid is supplied from the reservoir tank 2 to the primary fluid chamber 5 2 and the secondary fluid chamber 5 4. 【0036】 [0 0 1 5] When the driver presses the brake pedal 8 0, the power assist device 9 0 activates, and the pedal force is amplified at a predetermined servo ratio and output. The output of the power assist device 9 0 activates the primary piston 5 1 of the master cylinder 5 0, supplying brake fluid from the primary fluid chamber 5 2 to the wheel cylinder 6 0 of one system. Meanwhile, the secondary piston 5 3 activates, supplying brake fluid from the secondary fluid chamber 5 4 to the wheel cylinder 6 0 of the other system. When the lost stroke of each brake system is eliminated, the master cylinder 5 0 generates hydraulic pressure. When this hydraulic pressure from the master cylinder 5 0 is transmitted to each wheel cylinder 6 0, each wheel cylinder 6 0 generates braking force, and the brakes are applied to each wheel 7 0. 【0037】[0 0 1 6] The reservoir tank 2 according to the present invention may be used in hydraulic brake systems other than those shown in Figure 1. For example, the hydraulic brake system may have a hydraulic control unit between the master cylinder 5 0 and the wheel cylinder 6 〇 that performs anti-lock brake control and vehicle stabilization control. In another example, the hydraulic brake system may be configured without a doubler device 9 〇. 【0038】 [ 0 0 1 7 ] 【0039】 (Reservoir Tank) The reservoir tank 2 has a passage chamber 4 having a primary port 21 and a secondary port 22 connected to the master cylinder 50, and a storage chamber 3 that communicates with the passage chamber 4 and is located in the front direction F (forward direction F) of the vehicle, relative to the primary port 21 and the secondary port 22. Brake fluid stored in the storage chamber 3 is supplied to the master cylinder 50 through the passage chamber 4. A float sensor 6 (dashed line in Figure 1) for detecting the amount of brake fluid is located inside the storage chamber 3. In this embodiment, when the vehicle on which the reservoir tank 2 is mounted is in a horizontal position, the passage chamber 4 is formed to have a bottom surface that slopes upward toward the front direction F of the vehicle. This is to facilitate the flow of brake fluid stored in the storage chamber 3 through the passage chamber 4 toward the primary port 21 and the secondary port 22. 【0040】 [0 0 1 8] The reservoir tank 2 is composed of a lower body 10, an upper body 30, and a cover body 40, all molded from plastic. The reservoir tank 2 is formed by fusion bonding of the lower body 10 and the upper body 30, and the upper body 30 and the cover body 40. 【0041】[0 0 1 9] Figure 2 is a schematic diagram of the lower body 10 viewed from above. The lower body 10 is formed in a container shape and has an outer peripheral wall 11 surrounding it and a plurality of ribs 12 formed inside it. The lower part of the passage chamber 4 is formed in the lower body 10, and the passage chamber 4 has a primary passage 23 that leads brake fluid to the primary port 21 and a secondary passage 24 that leads brake fluid to the secondary port 22. 【0042】 [0 0 2 0] In Figure 2, the projection position of the communication port 31 provided in the upper body is shown by a dashed line. The communication port 31 is an opening that connects the storage chamber 3 and the passage chamber 4, and the brake fluid from the storage chamber 3 is guided to the passage chamber 4 through the communication port 31. 【0043】 [ 0 0 2 1 ] The primary passage 2 3 is formed to extend from the communication opening 3 1, once towards the front of the vehicle F, make a U-turn at the primary notch 2 5, and then proceed towards the rear of the vehicle R (rear direction R) to reach the primary port 2 1. In the route from the primary notch 2 5 toward the rear direction R, the primary passage 2 3 is formed as a region enclosed by the outer peripheral wall and the rib 1 2, and in part of the passage has a primary recess 2 7 a in which the rib recesses toward the secondary passage 2 4. and / or, in the route from the primary notch 2 5 toward the rear direction R, the primary passage 2 3 has a primary protrusion 2 7 b in part of the passage that protrudes from the outer peripheral wall into the primary passage 2 3. 【0044】

[0022] The secondary passage 24 is provided adjacent to the primary passage 23. The secondary passage 24 is formed such that from the communication port 31, it first heads in the forward direction F of the vehicle, makes a U-turn at the secondary notch 26, and then heads in the rearward direction R to reach the secondary port 22. In the route from the secondary notch 26 toward the rearward direction R, the secondary passage 24 is formed as a region surrounded by the outer peripheral wall 11 and the rib 12, and in a part of the passage, the rib 12 has a secondary recess 28a that is recessed in the direction of the primary passage 23. And / or, in the route from the secondary notch 26 toward the rearward direction R, the secondary passage 24 has a secondary protrusion 28b that protrudes from the outer peripheral wall 11 into the secondary passage 24 in a part of the passage. Note that in this embodiment, the primary passage 23 is provided on the right side and the secondary passage 24 is provided on the left side when heading in the rearward direction R, but the primary passage 23 may be provided on the left side and the secondary passage 24 may be provided on the right side. 【0045】

[0023] In FIG. 2, the fusion bonding portion that is fusion bonded to the upper body is the tip portion of the outer peripheral wall, rib, etc. For the fusion bonding, for example, hot plate welding is used. 【0046】

[0024] FIG. 3 is a schematic view of the upper body 30 seen from below. The upper body 30 has an upper portion of the passage chamber 4 provided corresponding to the lower body 10. The communication port 31 described above is provided in the passage chamber 4 of the upper body 30. The upper body 30 has a lower portion of the storage chamber 3 that further protrudes in the forward direction F of the vehicle from the passage chamber 4. The lower portion of the storage chamber 3 is formed as a container-shaped portion that opens in the opposite direction to the upper portion of the passage chamber 4. In the upper body 30, upper portions such as the primary passage 23, the primary recess 27a, the primary protrusion 27b, the secondary passage 24, the secondary recess 28a, and the secondary protrusion 28b are formed corresponding to the lower body 10. 【0047】

[0025] On the upper part of the cover body 40, a brake fluid inlet 5 (see FIG. 1) is formed, and brake fluid is replenished from the brake fluid inlet 5 to the reservoir tank 2. The brake fluid inlet 5 is formed to be sealable by a cap 7 (see FIG. 1). A similar fusion joint is also provided between the upper body 30 and the cover body 40. The reservoir tank 2 formed in this way has only the brake fluid inlet 5, the primary port 21, and the secondary port 22 opening to the outside of the reservoir tank. The primary port 21 and the secondary port 22 are respectively connected to the primary fluid chamber 52 and the secondary fluid chamber 54 of the master cylinder 5〇. 【0048】

[0026] FIG. 4 is a cross-sectional view of three planes perpendicular to the longitudinal direction of the reservoir tank 2 (the cross-section location is shown in FIG. 2). The three cross-sectional views are the C - C cross-sectional view, the D - D cross-sectional view, and the E - E cross-sectional view. FIG. 4 shows these arranged with the height directions aligned. The C - C cross-section is a cross-section passing through the primary notch 25 and the secondary notch 26. The D - D cross-section is a cross-section passing through the secondary protrusion 28b. The E - E cross-section is a cross-section passing through the primary port 21. Between the C - C cross-section and the D - D cross-section, a communication port 31, a primary recess 27a, a primary protrusion 27b, a secondary recess 28a, etc. are included. Between the D - D cross-section and the E - E cross-section, the secondary port 22, etc. are included. 【0049】

[0027] 【0050】In the C-C section, the ceiling height H1 of primary passage 2 3 is higher than the ceiling height H2 of primary passage 2 3 in the D-D section. Also, the ceiling height H2 of primary passage 2 3 in the D-D section is higher than the ceiling height H3 of primary passage 2 3 in the E-E section. Thus, the ceiling height of primary passage 2 3 is formed to slope upward toward the front direction F of the vehicle. Furthermore, the ceiling height of secondary passage 2 4 is formed in the same way as the ceiling height of primary passage 2 3. 【0051】 [ 0 0 2 8 ] 【0052】 In the C-C section, the bottom height B1 of primary passage 2 3 is higher than the bottom height B2 of primary passage 2 3 in the D-D section. Also, the bottom height B2 of primary passage 2 3 in the D-D section is higher than the bottom height B3 of primary passage 2 3 in the E-E section. As mentioned above, the bottom height of primary passage 2 3 is formed to slope upward toward the front direction F of the vehicle. The bottom height of secondary passage 2 4 is formed in the same way as the bottom height of primary passage 2 3. Ceiling height and bottom height are heights based on a predetermined horizontal plane height position. 【0053】 [0 0 2 9] As the brake pads thin, the brake fluid moves in the direction of the wheel cylinder 6, causing the fluid level in the reservoir chamber 3 to drop. Figure 5 explains the reservoir tank 2 with the lowered brake fluid level using the C-C cross-sectional view of Figure 4. Figure 5(a) shows the case when the vehicle is moving straight. The brake fluid level in this case is shown as L1 in the figure. In Figure 5(a), the area above the fluid level enclosed by the outer wall 11 and the rib 12 is called region S. In Figure 5(a), region S is an empty space. 【0054】[ 0 0 3 0 ] Here, as the vehicle begins to turn to the right, the liquid surface tilts in accordance with the centrifugal force generated, and region S gradually decreases. Figure 5(b) shows the state where region S becomes zero due to the tilt of the liquid surface L2. Normally, the air that was in region S in Figure 5(a) escapes through the primary notch 25 and out of the communication port 31 as the liquid surface tilts. However, if the centrifugal force increases rapidly, the air that was in region S may not escape completely and may become trapped in the brake fluid between the outer wall 11 and the rib 12. If the master cylinder 5〇 operates to draw in fluid in this state, the trapped air will move towards the primary port 21. If this air enters the brake piping from the primary port 21, it may lead to malfunctions such as a decrease in the hydraulic pressure rise. However, according to the reservoir tank 2 of the present invention, air drawn into the brake fluid moves through the primary passage 2 3 due to the suction operation of the master cylinder 50, but is trapped by trap structures such as the primary recess 2 7 a or primary protrusion 2 7 b provided along the way and does not reach the primary port 2 1. 【0055】 [0 0 3 1] Figure 6 shows how the air is trapped. Figure 6 is an enlarged view of the lower left part of Figure 2. The air drawn in at position G moves towards the primary port 21 due to the suction action of the master cylinder 5〇, but first its movement is blocked by the primary protrusion 27b (position K). Then, even if it moves further, it is trapped by the primary recess 27a which is provided to cover the tip of the primary protrusion 27b (position L), and the drawn-in air cannot move any further towards the primary port 21. After that, as the vehicle's turning motion ends and the liquid level returns to normal, the trapped air moves along the inclined ceiling surface towards the primary notch 25 (route I), so the trapped air after the vehicle's turning motion does not reach the primary port 21. 【0056】[0 0 3 2] Figure 7 is a superimposed view of the C-C section (solid line) and the E-E section (dashed line) of Figure 4, showing a state where centrifugal force is applied to the vehicle, as indicated by the liquid level L3. Similar to (b) in Figure 5, the region S is zero due to the inclination of the liquid level L3 (see the solid line section). Also, the opening of the primary port 21 (see the dashed line section) is above the liquid level L3. In such a reservoir tank, even if a very small amount of air is drawn into the brake fluid and reaches the primary port 21, there is a high possibility that the fluid suction of the master cylinder 50 will be impaired. In the reservoir tank 2 of the present invention, even a very small amount of air drawn into the brake fluid is trapped by the trap structure such as the primary recess 27a or primary protrusion 27b, and does not reach the primary port 21, so the fluid suction of the master cylinder 50 is not impaired. Even when the opening of the primary port 2 1 (see the dashed cross-sectional view) is above the liquid level L 3, the liquid suction of the master cylinder 5 0 is not impaired according to the present invention. 【0057】 [0 0 3 3] Although not shown in the diagram, if the vehicle turns left, air entrainment that occurs in the primary passage 23 may also occur in the secondary passage 24. However, according to the present invention, the air entrained in the brake fluid moves through the secondary passage 24 due to the suction operation of the master cylinder 50, but is trapped in the secondary recess 28a or secondary protrusion 28b provided along the way and does not reach the secondary port 22. As the vehicle's turning motion ends and the fluid level returns to normal, the trapped air moves along the inclined ceiling surface towards the secondary notch 26, so the trapped air does not reach the secondary port 22 after the vehicle's turning motion. 【0058】[0 0 3 4] According to the present invention, in a reservoir tank 2 in which the storage chamber 3 is positioned shifted forward of the vehicle from the master cylinder 5〇, even if air is drawn into the brake fluid within the reservoir tank 2, it is possible to provide a reservoir tank 2 in which the drawn-in air is not drawn into the master cylinder 5〇. 【0059】 [Explanation of symbols] 【0060】 [ 0 0 3 5 ] 【0061】 1 Hydraulic brake system, 2 Reservoir tank, 3 Storage chamber, 4 Passage chamber, 5 Brake fluid inlet, 6 Float sensor, 7 Cap, 1 Lower body, 1 Outer wall, 1 Rib, 2 Primary port, 2 Secondary port, 2 Primary passage, 2 Secondary passage, 2 Primary notch, 2 Secondary notch, 2 7 a Primary recess, 2 7 b Primary protrusion, 2 8 a Secondary recess, 2 8 b Secondary protrusion, 3 Upper body, 3 Communication port, 4 Cover, 5 Master cylinder, 5 Primary piston, 5 Primary fluid chamber, 5 Secondary piston, 5 Secondary fluid chamber, 6 Wheel cylinder, 70 wheels, 80 brake pedal, 90 multiplier device.

Claims

[Document Name] Scope of Claim [Claim 1] A reservoir tank (2) for storing brake fluid to be supplied to a master cylinder (50) attached to a vehicle, wherein the reservoir tank (2) has a passage chamber (4) having a primary port (21) and a secondary port (22), and a storage chamber (3) communicating with the passage chamber (4) and provided in a forward direction of the vehicle beyond the primary port (21) and the secondary port (22), wherein the passage chamber (4) has a primary passage (23) which is a passage connecting the storage chamber (3) and the primary port (21), and a secondary passage (24) which is a passage connecting the storage chamber (3) and the secondary port (22), and the primary passage (23) and / or the secondary passage (24) In the middle of this, there is a reservoir tank (2) with a trap structure that captures air drawn into the brake fluid. [Claim 2] The reservoir tank (2) according to claim 1, wherein the trap structure is a recess (27a, 28a) provided in a rib (12) that demarcates the primary passage and / or the secondary passage. [Claim 3] The reservoir tank according to claim 1, wherein the trap structure is a protrusion (27b, 28b) provided on the outer peripheral wall (11) that demarcates the primary passage and / or the secondary passage. [Claim 4] A hydraulic brake device (1) having a reservoir tank (2) according to any one of claims 1 to 3. 7

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