Bush-type hydraulic mount

Abstract

The present invention relates to a vehicle mount, and more specifically, to a bushing-type fluid mount applied to the mounting of a motor module of an electric vehicle. The bushing-type fluid mount according to the present invention comprises: an inner pipe; an intermediate pipe arranged concentrically with the inner pipe; a main rubber vulcanized between the inner pipe and the intermediate pipe; and an outer pipe surrounding the intermediate pipe, wherein the main rubber comprises: a front fluid chamber recessed radially from the surface; a rear fluid chamber adjacent to the front fluid chamber and recessed radially from the surface; and a bridge that separates the front fluid chamber and the rear fluid chamber so as to be fluidly communicable and is deformable by an external force.

Description

Technology Field

[0001] The present invention relates to a vehicle mount, and more specifically, to a bushing-type fluid mount applied to the mounting of a motor module of an electric vehicle. Background Technology

[0002] Recently, active research and development on eco-friendly electric vehicles (EVs) has been underway. EVs are driven by motors instead of conventional engines and are powered by rechargeable batteries rather than petroleum fuels.

[0003] In the case of electric vehicles, motors are generally mounted using a center-supported system because internal low-frequency vibrations are minimal. Additionally, since the weight of the motor module, which includes the motor and power electronics, is smaller than that of a conventional engine, bush-type rubber mounts are used instead of fluid mounts.

[0004] However, bush-type rubber mounts have very low axial characteristics due to shape limitations. Consequently, there is a problem where axial movement increases, causing severe vibration when passing over plastic protrusions. To improve this problem, an additional mount point, such as a torque rod, is often added in the axial direction, but this is disadvantageous in terms of package layout and assembly, and increases cost and volume. Prior art literature

[0005] Published Patent Application No. 10-2019-0025401 (Date of publication: March 11, 2019) The problem to be solved

[0006] The present invention has been devised to solve the aforementioned problems, and

[0007] The purpose is to provide a bush-type fluid mount for electric vehicles that can improve aftershock sensitivity by enhancing axial characteristics.

[0008] At the same time, the present invention aims to provide a bush-type fluid mount capable of minimizing cost and weight increase.

[0009] The objectives of the present invention are not limited to those mentioned above, and other unmentioned objectives will be clearly understood by those skilled in the art to which the present invention pertains (hereinafter referred to as "person skilled in the art") from the description below. means of solving the problem

[0010] The features of the present invention for achieving the objectives of the present invention as described above and for performing the characteristic functions of the present invention described below are as follows.

[0011] A bush-type fluid mount according to the present invention comprises: an inner pipe; an intermediate pipe arranged concentrically with the inner pipe; a main rubber vulcanized between the inner pipe and the intermediate pipe; and an outer pipe surrounding the intermediate pipe, wherein the main rubber comprises: a front fluid chamber recessed radially from the surface; a rear fluid chamber adjacent to the front fluid chamber and recessed radially from the surface; and a bridge that separates the front fluid chamber and the rear fluid chamber so as to be fluidly communicable and deformable by an external force.

[0012] A method for assembling a bush-type fluid mount according to the present invention comprises the steps of: arranging an intermediate pipe including an opening concentrically with an inner pipe arranged radially inward; vulcanizing a main rubber between the inner pipe and the intermediate pipe; - the main rubber includes a front fluid chamber recessed from the surface of the main rubber; a rear fluid chamber adjacent to the front fluid chamber and recessed from the surface of the main rubber; and a bridge formed between the front fluid chamber and the rear fluid chamber, protruding radially outward from the intermediate pipe and deformable by an external force, wherein the length of a first side, which is one side of the bridge, is formed to be longer than the length of a second side, which is the opposite side of the first side; and inserting an outer pipe from the second side to surround the outer side of the intermediate pipe. Effects of the invention

[0013] According to the present invention, a bushing-type fluid mount for an electric vehicle is provided that can improve the sensation of vibration by improving axial characteristics.

[0014] In addition, according to the present invention, a bushing-type fluid mount is provided that can minimize cost and weight increase.

[0015] The effects of the present invention are not limited to those described above, and other unmentioned effects will be clearly recognized by a person skilled in the art from the description below. Brief explanation of the drawing

[0016] FIG. 1a illustrates a motor module mounting system for an electric vehicle, and FIG. 1b illustrates a conventional bush-type rubber mount, and FIG. 2 illustrates a cross-sectional view along line A-A' of FIG. 1b, and FIG. 3a shows a perspective view of one side of a bush-type fluid mount according to the present invention, and FIG. 3b is a perspective view of the other side of FIG. 3a, illustrating a bush-type fluid mount viewed from below, and FIG. 4a illustrates a cross-sectional view of a bush-type fluid mount according to the present invention, and FIG. 4 illustrates a bush-type fluid mount according to the present invention, and FIG. 5 is a side view of a bush-type fluid mount according to the present invention, showing an outer pipe omitted, and FIGS. 6a to 6h illustrate the assembly process of a bush-type fluid mount according to the present invention, and Figures 7a and 7b compare the behavioral characteristics of the embodiments and comparative examples of the present invention. Specific details for implementing the invention

[0017] The specific structural or functional descriptions presented in the embodiments of the invention are merely illustrative for the purpose of explaining embodiments according to the concept of the invention, and embodiments according to the concept of the invention may be implemented in various forms. Furthermore, it should not be interpreted as being limited to the embodiments described herein, but should be understood to include all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0018] Meanwhile, in the present invention, terms such as "first" and / or "second" may be used to describe various components, but said components are not limited to said terms. For the sole purpose of distinguishing one component from other components, for example, without departing from the scope of rights according to the concept of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0019] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly in contact" with another component, it should be understood that there are no other components in between. Other expressions used to describe the relationship between components, such as "between" and "exactly between," or "adjacent to" and "directly adjacent to," should be interpreted in the same way.

[0020] Throughout the specification, identical reference numbers denote identical components. Meanwhile, the terms used in this specification are for describing embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used in this specification, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0022] The present invention will be described in detail below with reference to the attached drawings.

[0023] FIG. 1a illustrates a state in which a motor module in an electric vehicle is mounted by a bush-type rubber mount (500) arranged in the front-rear direction and left-right direction mounts (600a, 600b). In FIG. 1a, FW represents the front of the vehicle.

[0024] In the case of a bush-type rubber mount on an electric vehicle platform, the axial characteristics are lower compared to the left-right or up-down directions. For example, referring to Fig. 1b, it has been confirmed that the characteristic X1 in the X direction (axial) of the bush-type rubber mount is 20 kgf / mm, the characteristic Y1 in the Y direction (left-right) is 65 kgf / mm, and the characteristic Z1 in the Z direction (up-down) is 65 kgf / mm.

[0025] Therefore, in order to increase the left-right directional characteristics, the axial direction of the mount (500) located at the front is positioned in the X direction, which is the front-rear direction of the vehicle. At this time, the axial characteristics of the mount (500) are low, so the aftershock sensation becomes severe. In this case, the axial characteristics should be improved, but it is impossible to improve the axial characteristics due to the characteristics resulting from the bush-type rubber mount shape.

[0026] The present invention aims to provide a bush-type fluid mount (1) capable of solving these problems. The bush-type fluid mount (1) according to the present invention is a fluid-enclosed bush-type fluid mount having axial damping, designed particularly for electric vehicles. Bush-type mounts have high vertical and horizontal characteristics, but there is a limit to the improvement of axial characteristics. As an alternative to this, the present invention proposes a bush-type fluid mount that minimizes axial movement by having axial damping.

[0027] FIG. 2 shows a cross-sectional view of a conventional bush-type rubber mount (500). The bush-type rubber mount (500) is formed by vulcanizing rubber (520) between an inner pipe (510) and an outer pipe (530) arranged concentrically. The present invention provides a bush-type fluid mount (1) having improved axial characteristics by adding only a very small number of parts compared to the conventional bush-type rubber mount (500).

[0028] As illustrated in FIG. 3a, the bushing fluid mount (1) according to the present invention comprises an inner pipe (20), a main rubber (40), an intermediate pipe (60), and an outer pipe (80).

[0029] The inner pipe (20), the middle pipe (60), and the outer pipe (80) are arranged concentrically, and the main rubber (40) is vulcanized between the inner pipe (20) and the middle pipe (60).

[0030] According to the present invention, a bushing-type fluid mount (1) can maximize the damping value by configuring two sets of fluid chambers and fluid paths in the vertical direction. To this end, according to an embodiment of the present invention, the main rubber (40) includes a front fluid chamber (140), a rear fluid chamber (240), a first fixing part (340), a bridge (440), a second fixing part (540), a fluid path (640), and a guide part (740). That is, the front fluid chamber (140), the rear fluid chamber (240), the first fixing part (340), the bridge (440), the second fixing part (540), the fluid path (640), and the guide part (740) can each be formed vertically symmetrically with respect to the axial direction of the bushing-type fluid mount (1).

[0031] The front fluid chamber (140) and the rear fluid chamber (240) are separated by a bridge (440) and configured to be fluidly connected to each other. The front fluid chamber (140) is provided between the first fixed part (340) and the bridge (440) in the axial direction of the bush-type fluid mount (1), and the rear fluid chamber (240) is provided between the bridge (440) and the second fixed part (540) in the axial direction of the bush-type fluid mount (1). The first fixed part (340) and the second fixed part (540) are fixed to the intermediate pipe (60), and the bridge (440) can move relative to the intermediate pipe (60) as described later.

[0032] The front fluid chamber (140) and the rear fluid chamber (240) are accommodating fluid and are formed by being recessed radially inward from the surface of the main rubber (40) to accommodate fluid.

[0033] A bridge (440) is located between the front extrusion (140) and the rear extrusion (240). The bridge (440) is formed integrally with the main rubber (40) and is configured to be deformable by an external force. According to an embodiment of the present invention, the bridge (440) includes a front portion (442), a contact portion (444), and a rear portion (446) (see FIG. 4a).

[0034] The front portion (442) is in direct contact with the front fluid chamber (140), and the rear portion (446) is in direct contact with the rear fluid chamber (240). The contact portion (444) is in contact with the outer pipe (80), and the contact position and area with respect to the outer pipe (80) can change due to external force.

[0035] The bridge (440) has a thickness that gradually decreases toward the radial outer side of the bush-type fluid mount (1). Additionally, the bridge (440) is configured with a tapered shape that is biased to one side as its thickness decreases toward the radial outer side. To this end, according to an embodiment of the present invention, the length of the front portion (442) is formed to be shorter than the length of the rear portion (446). Through such a shape, the bridge (440) is deformed or bent in only one direction, and durability, joints, and assembly can be improved.

[0036] As shown in FIG. 5, the bridge (440) is formed to be longer radially outward than the first fixing part (340) or the second fixing part (540). Accordingly, the bridge (440) protrudes radially outward by a length d further than the intermediate pipe (60). According to an embodiment of the present invention, the bridge (440) protrudes approximately 3 to 5 mm radially outward relative to the intermediate pipe (60).

[0037] The front fluid chamber (140) and the rear fluid chamber (240) are fluidly connected by a fluid path (640). The fluid contained in each of the front fluid chamber (140) and the rear fluid chamber (240) can move to the other fluid chamber along the fluid path (640) when the front fluid chamber (140) or the rear fluid chamber (240) expands or contracts due to an external force.

[0038] The Euro (640) is formed by being recessed from the surface of the main rubber (40), such as the front fluid chamber (140) and the rear fluid chamber (240). According to an embodiment of the present invention, the depth of the recess of the Euro (640) is smaller than the depth of the front fluid chamber (140) and the rear fluid chamber (240).

[0039] The cross-sectional area of ​​the fluid passage (640) can be increased or decreased through the guide section (740). The size of the inlet of the front fluid chamber (140) and the rear fluid chamber (240) can be adjusted by adjusting the size of the guide section (740). The guide section (740) can be provided by forming a fluid passage (640) that connects the front fluid chamber (140) and the rear fluid chamber (240). That is, the guide section (740) is formed at the same height as the surface of the first fixed section (340) and the second fixed section (540) or the main rubber (40), and is higher than the fluid passage (640). According to the present invention, since the length and / or width of the fluid passage (640) formed in the main rubber (40) itself is adjustable, the damping frequency, etc., can be tuned.

[0040] Referring to FIG. 3b, according to an embodiment of the present invention, the fluid passage (640) may be formed symmetrically with respect to the center point of the bush-type fluid mount (1) or axially symmetrically with respect to the axis of the bush-type fluid mount (1). That is, when a fluid passage (640) is formed on the upper side and the lower side of a bush-type fluid mount (1), the upper fluid passage (640) and the lower fluid passage (640) are provided at positions symmetrical to each other with respect to the axial direction with respect to the axis of the bush-type fluid mount (1).

[0041] The upper guide section (740) and the lower guide section (740) adjacent to the upper fluid passage (640) and the lower fluid passage (740), respectively, are also arranged axially symmetrically with respect to the axis of the bush-type fluid mount (1). As a result, two dampings are added to the vertical movement of the bush-type fluid mount (1), thereby maximizing the damping.

[0042] The operation of the bush-type fluid mount (1) according to the present invention is explained through the case where an axial force is applied to the bush-type fluid mount (1) in the direction of the arrow in Fig. 4a.

[0043] Before a force is applied in the direction of the arrow, the bridge (440) is in position P. When an axial force is applied in the direction of the arrow, the fixed first fixing part (340) and the second fixing part (540) are maintained in their original positions, and the bridge (440) moves to position P1 as it slides rearward from the outer pipe (80). The fluid contained in the front fluid chamber (140) and the rear fluid chamber (240) is an oil component, so the coefficient of friction is low, causing the bridge (440) to slide. At this time, the volume of the front fluid chamber (140) increases, and the volume of the rear fluid chamber (240) decreases.

[0044] The bridge (440) is formed such that the rear portion (446) is longer than the front portion (442), and when the outer pipe (80) is inserted, as described below, the end of the rear portion (446) forms a contact portion (444), so that the bridge (440) can be bent in only one direction, and the bridge (440) does not shake left or right when the bush-type fluid mount (1) moves axially. This provides improved durability and can prevent noise that may occur when the direction of the bridge (440) changes.

[0045] As shown in FIG. 4b, as the rear fluid chamber (240) contracts, the fluid contained in the rear fluid chamber (240) moves along the flow path (640) in the direction W toward the front fluid chamber (140), providing damping. In particular, since two front fluid chambers (140) and two rear fluid chambers (240) are provided symmetrically with respect to the axial direction on both the upper and lower sides of the bush-type fluid mount (1), two dampings are added for vertical movement, thereby maximizing damping.

[0046] The assembly process of the bush-type fluid mount (1) according to the present invention is explained with reference to FIGS. 6a to 6h.

[0047] The inner pipe (20) is positioned within the middle pipe (60), and the main rubber (40) is vulcanized. The front chamber (140), rear chamber (240), and bridge (440), etc., are positioned in the opening formed in the middle pipe (60).

[0048] The assembly of the outer pipe (80) is performed in a liquid, and at this time, the inside of the bush-type fluid mount (1) is filled with fluid. The outer pipe (80) is inserted from the longer rear portion (446). When the outer pipe (80) is slid axially, the bridge (440) is compressed, and the front fluid chamber (140) and the rear fluid chamber (240) are separated. As the outer pipe (80) is joined, the outer pipe (80) pressurizes the bridge (440) which protrudes radially outward from the middle pipe (60), and the end of the bridge (440) bends forward. As the longer rear portion (446) bends forward, a part of the end of the rear portion (446) forms a contact portion (444). Once the joining of the outer pipe (80) is completed, swaging for sealing is performed on the first fixing portion (340) and the second fixing portion (540).

[0049] Figures 7a and 7b compare the front-rear characteristics of the embodiments of the present invention and comparative examples. Comparative Example 1 used a conventional bush-type rubber mount with front-rear characteristics of 20 kgf / mm, and Comparative Example 2 used a bush-type rubber mount with increased front-rear characteristics of 27 kgf / mm. In the case of Comparative Example 2, the rubber characteristics were increased to a hardness of HS70 for principle evaluation, but as shown in the figure, it was confirmed that there was no improvement effect or that it deteriorated in some areas.

[0050] Here, HS70 refers to the hardness of the vulcanized rubber, and the higher the number, the higher the rubber's properties. Generally, HS35 to HS65 rubber is used for mounts, but HS70 was applied for the principle test. In the embodiment of the present invention, it was confirmed that the excitation sensation is improved when front-rear damping is applied. In particular, it was confirmed that the characteristics are improved up to a frequency range of 13 to 18 Hz.

[0051] In conventional bush-type rubber mounts, the inability to increase axial characteristics resulted in excessive forward and backward movement of the motor module in electric vehicles, causing severe aftershock sensation. According to the present invention, the aftershock sensation can be improved by adding an axial damping value.

[0052] The present invention can also minimize cost and weight increase by adding only a minimum number of parts compared to a standard bush-type mount. Compared to a bush-type rubber mount, it includes an intermediate pipe (60) and a sealed fluid, and in particular, the flow path (640) can be formed in the main rubber (40) itself through vulcanization to minimize cost and weight increase.

[0053] The present invention can provide damping performance through an axle configuration based on forward and backward movement using a bridge compression design method. This configuration is achieved through the vulcanization of the main rubber, resulting in no increase in cost or weight.

[0054] According to the present invention, the bridge (440) is formed in a tapered shape biased toward one side, and since the bridge (440) is bent only toward one side so that the shape can be maintained constant during axial movement, it is possible to improve durability, reduce joints, and improve assembly.

[0055] In addition, the present invention enables the optimization of a motor mounting system by configuring the axle in an up-and-down symmetrical manner and distinguishing characteristics in three directions.

[0056] The present invention described above is not limited by the aforementioned embodiments and attached drawings, and it will be obvious to those skilled in the art that various substitutions, modifications, and changes are possible within the scope of the technical concept of the present invention. Explanation of the symbols

[0057] 1: Bush-type fluid mount 20: Inner pipe 40: Main rubber 60: Middle pipe 80: Outer pipe 140: Front excis 240: Rear extrusion 340: First fixing part 440: Bridge 442: Forward section 444: Contact area 446: Rear area 540: 2nd fixed part 640: Euro 740: Information Department

Claims

Claim 1 It comprises: an inner pipe; an intermediate pipe arranged concentrically with respect to the inner pipe; a main rubber vulcanized between the inner pipe and the intermediate pipe; and an outer pipe surrounding the intermediate pipe; wherein the main rubber comprises: a front fluid chamber recessed from the surface; a rear fluid chamber adjacent to the front fluid chamber and recessed from the surface; a bridge that fluidly separates the front fluid chamber and the rear fluid chamber and is deformable by an external force; and a flow path formed recessed from the surface of the main rubber and connecting the front fluid chamber and the rear fluid chamber, wherein the front fluid chamber, the rear fluid chamber, the bridge, and the flow path are each arranged symmetrically vertically with respect to the axial direction of the intermediate pipe but are separated from each other, and the bridge comprises: a front portion in contact with the front fluid chamber; and a contact portion in contact with the inner circumference of the outer pipe. A bushing-type fluid mount comprising a rear portion in contact with the rear fluid seal, wherein the length of the rear portion is formed to be longer than the length of the front portion so that the bridge bends only in one direction, and the end of the rear portion constitutes the contact portion. Claim 2 delete Claim 3 A bushing-type fluid mount according to claim 1, wherein the contact portion contacts the outer pipe and is movable relative to the outer pipe by an external force. Claim 4 delete Claim 5 A bush-type fluid mount according to claim 1, wherein the bridge is formed to be longer radially outward than the intermediate pipe. Claim 6 A bush-type fluid mount according to claim 3, wherein the bridge forms the contact portion that contacts the outer pipe while being bent toward the insertion direction of the outer pipe by insertion into the outer pipe. Claim 7 A bush-type fluid mount according to claim 1, wherein the bridge has a tapered shape that is biased to one side and has a thickness that decreases toward the radial outer side of the main rubber. Claim 8 delete Claim 9 delete Claim 10 A bushing fluid mount according to claim 3, wherein the bridge is configured to bend to only one side with respect to the axial direction of the bushing fluid mount. Claim 11 A bushing-type fluid mount according to claim 1, wherein the main rubber is formed by the front fluid chamber, rear fluid chamber, bridge, and fluid path, and further comprises a guide portion adjacent to the front fluid chamber, rear fluid chamber, bridge, and fluid path. Claim 12 A bushing-type fluid mount according to claim 11, wherein the fluid path and guide are arranged axially symmetric with respect to the axis of the intermediate pipe. Claim 13 A step of arranging an intermediate pipe including an opening concentrically with an inner pipe positioned radially inward; a step of vulcanizing a main rubber between the inner pipe and the intermediate pipe; - the main rubber comprises: a front chamber recessed from the surface of the main rubber; a rear chamber adjacent to the front chamber and recessed from the surface of the main rubber; a bridge formed between the front chamber and the rear chamber, protruding radially outward from the intermediate pipe and deformable by external force; and a flow path formed recessed from the surface of the main rubber and connecting the front chamber and the rear chamber; and a step of inserting an outer pipe from a second side to surround the outer side of the intermediate pipe; wherein the front chamber, rear chamber, bridge, and flow path are each arranged symmetrically vertically with respect to the axial direction of the intermediate pipe but are separated from each other, and the bridge comprises: a front portion in contact with the front chamber; and a contact portion in contact with the inner circumference of the outer pipe. A method of assembling a bushing-type fluid mount comprising a rear portion that contacts the rear fluid seal, wherein the length of the rear portion is formed longer than the length of the front portion so that the bridge bends only in one direction, and the end of the rear portion constitutes the contact portion. Claim 14 A method for assembling a bush-type fluid mount according to claim 13, further comprising the step of swaging both ends of the outer pipe.

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