Method for manufacturing suspension bushing and suspension bushing

Abstract

The present application provides a method for manufacturing a suspension bushing and a suspension bushing, the method for manufacturing the suspension bushing comprising: obtaining a carrier member; the carrier member having a first end and a second end; the first end and the second end being bent in a direction approaching each other to form a first cavity; the carrier member having a first state and a second state, in the first state, the first end and the second end are separated from each other, and in the second state, the first end and the second end are in close contact with each other; when the carrier member is in the first state, the inner core of the bushing is placed in the first cavity, which forms a vulcanization cavity together with the carrier member, and rubber material is injected into the vulcanization cavity and vulcanized to obtain a first semi-finished part; compressing the first semi-finished part so that the carrier member switches from the first state to the second state, fixing the first end and the second end to obtain a second semi-finished part; the present application can manufacture suspension bushings with a large pre-compression amount.

Description

Technical Field

[0001] The present application relates to the technical field of engine suspension, and in particular to a method for manufacturing a suspension bushing and the suspension bushing. Background Art

[0002] With the rapid development of the automotive industry, demands for vehicle NVH (Noise, Vibration, Harshness) performance are becoming increasingly stringent. As a core component influencing vehicle NVH performance, the suspension system undoubtedly plays an increasingly important role. The suspension system primarily consists of three parts: the passive side bracket, the active side bracket, and the suspension bushing. The passive and active side brackets are generally made of metal, while the suspension bushing is a vulcanized rubber-metal composite. The vibration isolation performance of the suspension bushing is primarily determined by the performance of the suspension bushing.

[0003] The suspension bushing in the prior art generally includes a bushing shell, a bushing core, and a bushing rubber disposed between the bushing shell and the bushing core. The bushing shell is used to connect to the vehicle body, the bushing core is used to connect to the engine, and the bushing rubber includes multiple unconnected sections. The existence of each section enables the bushing rubber to form an upper gap located on the upper side of the bushing core, a lower gap located on the lower side of the bushing core, a left gap located on the left side of the bushing core, and a right gap located on the right side of the bushing core. The manufacturing process of the suspension bushing generally includes two steps: vulcanization and diameter reduction. Vulcanization refers to the vulcanization of rubber and metal, and diameter reduction refers to compressing the vulcanized suspension bushing from the outside to reduce its diameter. Based on the above manufacturing method, existing suspension bushings generally have the following three states:

[0004] First, the natural state, that is, the state of the suspension bushing just after vulcanization. At this time, the rubber gradually cools down after the vulcanization process, and there is a certain amount of residual stress inside. The upper gap corresponding to this state is a1 and the lower gap is b1;

[0005] Second, the state after diameter reduction, that is, the state after the suspension bushing has undergone the diameter reduction process and the internal stress is eliminated. The upper clearance in this state is a2 and the lower clearance is b2;

[0006] Third, the natural compression state, that is, the state of bearing the engine's own weight after the engine is assembled. At this time, the inner core of the bushing will move downward a certain distance with the engine. The upper clearance corresponding to this state is a3 and the lower clearance is b3.

[0007] like Figure 1-1 、 Figure 1-2 and Figure 1-3 The upper and lower clearance values ​​of the suspension bushing of a certain model of automobile shown in the figure under different states are: a1=1mm, b1=12mm; a2=0mm, b2=13mm; a3=5mm, b2=8mm.

[0008] During actual use, the engine always jumps up and down from time to time. At this time, theoretically, it is hoped that the suspension system will provide sufficient limiting stiffness to limit the engine's up and down jumping. Therefore, the most ideal state is: the suspension bushing is in a natural compression state, and the upper gap a3 is maintained at 1-2mm. At this time, the suspension bushing can provide sufficient vibration isolation and provide sufficient limiting at the initial stage of the engine jumping; in addition, with the improvement of NVH performance requirements, the engine's own weight compression size is gradually increasing, generally 6-8mm. Therefore, in order to obtain better NVH performance, the pre-compression amount needs to be set to 4-7mm, that is, when the suspension bushing is in the reduced diameter state, the upper gap a3 has a value of -4 to -7mm. The negative value means that the rubber on the upper and lower sides are in a state of mutual extrusion and deformation.

[0009] Existing methods for manufacturing suspension bushings often use tooling to forcibly compress the rubber bushing exoskeleton during diameter reduction. This method makes it impossible to compress the rubber bushing to a large extent. This means that it is difficult to achieve the ideal pre-compression amount for the suspension bushing in the reduced diameter state. Furthermore, the upper clearance of the suspension bushing in the naturally compressed state is large, which cannot provide sufficient limiting rigidity to limit the up and down movement of the engine, resulting in poor NVH performance. Therefore, this application proposes a method for manufacturing a suspension bushing and a suspension bushing. Summary of the Invention

[0010] The purpose of this application is to provide a method for manufacturing a suspension bushing and a suspension bushing in order to solve the above problems.

[0011] In a first aspect, the present application provides a method for manufacturing a suspension bushing, the method comprising the following steps:

[0012] Obtain a carrier member; the carrier member has a first end and a second end; the first end and the second end are bent in a direction toward each other to form a first cavity; the carrier member has a first state and a second state, in the first state, the first end and the second end are separated from each other, and in the second state, the first end and the second end are closely attached to each other;

[0013] When the carrier is in the first state, the bushing inner core is placed in the first cavity, and the bushing inner core and the carrier together form a vulcanization cavity. The rubber material is injected into the vulcanization cavity and vulcanized to obtain a first semi-finished product.

[0014] The first semi-finished product is compressed to switch the carrier from the first state to the second state, and the first end and the second end are fixed to obtain a second semi-finished product.

[0015] According to the technical solution provided in certain embodiments of the present application, when the carrier member is in the first state, the shape of the cross-section formed radially on the carrier member is a first circular ring with an opening, and on the side of the opening relatively far away from the center of the first circular ring, the line between the first end and the second end is the chord of the outer circle of the first circular ring; the outer circle diameter of the first circular ring is the first diameter.

[0016] According to the technical solution provided in certain embodiments of the present application, when the carrier member is in the second state, the shape of the cross-section formed radially on the carrier member is a closed second circular ring; the outer diameter of the second circular ring is a second diameter; and the second diameter is smaller than the first diameter.

[0017] According to the technical solutions provided in certain embodiments of the present application, the carrier member further has a third state; when the carrier member is in the third state, the cross-section formed along the radial direction of the carrier member is shaped as a closed third circular ring; the outer diameter of the third circular ring is a third diameter; and the third diameter is smaller than the second diameter;

[0018] After compressing the first semi-finished product so that the carrier component switches from the first state to the second state and fixing the first end and the second end to obtain a second semi-finished product, the following steps are further included:

[0019] The second semi-finished product is compressed so that the carrier part switches from the second state to the third state to obtain a finished product.

[0020] According to the technical solutions provided in certain embodiments of the present application, the step of obtaining the carrier member includes:

[0021] Obtaining a prefabricated steel pipe with a set length; the diameter of the prefabricated steel pipe is the second diameter;

[0022] An expansion seam is provided in the axial direction on the wall of the prefabricated steel pipe;

[0023] The prefabricated steel pipe with the expansion seam is expanded to obtain the carrier member in the first state.

[0024] According to the technical solutions provided in certain embodiments of the present application, an expansion device is used when expanding the prefabricated steel pipe with the expansion seam to obtain the carrier member in the first state; the expansion device includes:

[0025] A first fixing seat, wherein a receiving cavity is provided on the top of the first fixing seat;

[0026] A plurality of expansion members, all of which are distributed on a first circumference; the expansion members are in sliding connection with the bottom of the accommodating cavity in a radial direction along the first circumference;

[0027] A first driving mechanism is used to drive all the expansion members to move away from or toward each other simultaneously along the radial direction of the first circumference.

[0028] According to the technical solution provided in certain embodiments of the present application, the first driving mechanism includes a first telescopic driving device and a first driving member; the first telescopic driving device has a first telescopic driving end; the first driving member is a conical structure; the first telescopic driving end is fixedly connected to the large end of the first driving member; the central axis of the first driving member passes through the center of the first circle; all the expansion members are close to one end of the first driving member and together enclose a first conical space that matches the first driving member.

[0029] According to the technical solutions provided in certain embodiments of the present application, a compression device is used to compress the first semi-finished product when the carrier member switches from the first state to the second state; the compression device includes:

[0030] a second fixing seat, the second fixing seat having a first mounting surface;

[0031] A plurality of compression members, all of which are distributed on a second circumference; the compression members and the first mounting surface form a sliding connection along the radial direction of the second circumference;

[0032] The second driving mechanism is used to drive all the compression members to move away from or approach each other simultaneously along the radial direction of the second circumference.

[0033] According to the technical solution provided in certain embodiments of the present application, the second driving mechanism includes a second telescopic driving device and a second driving member; the second telescopic driving device has a second telescopic driving end; one end of the second driving member is connected to the second telescopic driving end, and the other end has a second conical space; the large end of the second conical space is arranged away from the second telescopic driving end; all the compression members together form a conical structure that matches the second conical space with one end away from the second fixed seat.

[0034] In the second aspect, the present application provides a suspension bushing, which is manufactured by the suspension bushing manufacturing method as described above, and the suspension bushing includes a bushing shell, a bushing core and a bushing rubber vulcanized between the two; the bushing shell is used to connect to the vehicle body; the bushing core is used to connect to the engine; the bushing rubber includes a main body covering the outside of the bushing core, and an upper limit portion distributed above the main body and vulcanized and fixed to the inner wall of the bushing shell; the main body and the upper limit portion are pressed and deformed against each other, and the sum of their deformations is equal to the target pre-compression amount.

[0035] Compared with the prior art, the beneficial effects of the present application are as follows: the manufacturing method of the suspension bushing provided by the present application, during the manufacturing process, first obtains a carrier member in which the first end and the second end are in a state of separation from each other, and places the bushing inner core into the first cavity formed by the carrier member to vulcanize the bushing rubber to obtain a first semi-finished product with a notch, and then compresses the first semi-finished product to eliminate the notch and achieve the fixation of the first end and the second end. The above method can produce a suspension bushing with a large pre-compression amount. When it is assembled with the engine and installed on the whole vehicle, the upper gap of the bushing rubber is small, which can effectively suppress the upward bounce of the engine, thereby being beneficial to vehicle vibration isolation, and further beneficial to obtaining better NVH performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1-1 A schematic diagram of a suspension bushing in a natural state in the prior art;

[0037] Figure 1-2 It is a schematic diagram of a suspension bushing in the prior art in a state after the diameter is reduced;

[0038] Figure 1-3 A schematic diagram of a suspension bushing in a natural compression state in the prior art;

[0039] Figure 2 A flow chart of a method for manufacturing a suspension bushing provided in an embodiment of the present application;

[0040] Figure 3 A schematic structural diagram of the prefabricated steel pipe with a set length obtained in step S11;

[0041] Figure 4 is a schematic structural diagram of the carrier member in the first state obtained in step S13;

[0042] Figure 5 is a schematic structural diagram of the expansion device used in step S13;

[0043] Figure 6 Schematic diagram of the structure of the inner core of the bushing;

[0044] Figure 7 is a structural schematic diagram of the first semi-finished product;

[0045] Figure 8 is a structural schematic diagram of the second semi-finished product;

[0046] Figure 9 is a schematic structural diagram of the compression device used in step S3;

[0047] Figure 10 This is a structural diagram of the finished suspension bushing.

[0048] The text annotations in the figure represent:

[0049] 1. Prefabricated steel pipe; 2. Carrier component; 3. Bushing inner core; 4. First semi-finished product; 5. Second finished product; 6. Bushing outer shell; 81. Main body; 82. Upper limit portion; 83. Left limit portion; 84. Right limit portion; 85. Lower limit portion; 86. Left main reinforcement; 87. Right main reinforcement;

[0050] 101. First fixing seat; 102. Expansion member; 103. First telescopic driving device; 104. First driving member;

[0051] 201. Second fixing seat; 202. Compression element; 203. Second telescopic driving device; 204. Second driving element. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is described in detail below with reference to the accompanying drawings. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present application.

[0053] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0054] This embodiment provides a method for manufacturing a suspension bushing, the flow chart of which is as follows: Figure 2 As shown, the method includes the following steps:

[0055] S1. Obtain a carrier member 2; the carrier member 2 has a first end and a second end; the first end and the second end are bent in a direction close to each other to form a first cavity; the carrier member 2 has a first state and a second state, in the first state, the first end and the second end are separated from each other, and in the second state, the first end and the second end are tightly attached to each other.

[0056] When the carrier member 2 is in the first state, the shape of the cross-section formed radially on the carrier member 2 is a first circular ring with an opening, that is, the carrier member 2 in the first state is a hollow cylindrical structure with openings at both ends, and a gap is provided on its side wall that passes through the openings at both ends, and the two ends of the gap are the first end and the second end of the carrier member 2; at the side of the opening of the first circular ring relatively away from the center of the first circular ring, the line between the first end and the second end is the chord of the outer circle of the first circular ring; the outer circle diameter of the first circular ring is the first diameter.

[0057] When the carrier member 2 is in the second state, the shape of the cross-section formed radially on the carrier member 2 is a closed second circular ring, that is, the carrier member 2 in the second state is a hollow cylindrical structure with openings at both ends; the outer diameter of the second circular ring is a second diameter; and the second diameter is smaller than the first diameter.

[0058] In this embodiment, the specific steps of obtaining the carrier 2 include:

[0059] S11. Obtain a prefabricated steel pipe 1 with a set length; the diameter of the prefabricated steel pipe 1 is the second diameter.

[0060] Specifically, an instrument cutting machine is used to cut the prefabricated steel pipe 1 into a set length. The prefabricated steel pipe 1 generally refers to a steel pipe whose outer diameter and wall thickness meet the design requirements. The wall thickness of the prefabricated steel pipe 1 is generally 1.5 mm. The outer diameter of the prefabricated steel pipe 1 is determined according to the design requirements of the suspension bushing and is generally 90-105 mm. The length of the entire prefabricated steel pipe 1 is generally 5 m. The prefabricated steel pipe 1 is cut by an instrument cutting machine to obtain a prefabricated steel pipe 1 with a set length, such as Figure 3 As shown, the set length is generally 50mm.

[0061] S12, an expansion seam is provided on the wall of the prefabricated steel pipe 1 along the axial direction.

[0062] The prefabricated steel pipe 1 obtained in step S11 is cut on one side, that is, an expansion seam is cut axially on the wall of the prefabricated steel pipe 1 so that the steel pipe can expand; the angle formed by the extension direction of the expansion seam and the central axis direction of the prefabricated steel pipe 1 is preferably controlled within 10°. Preferably, the extension direction of the expansion seam is parallel to the central axis direction of the prefabricated steel pipe 1 to facilitate subsequent expansion and subsequent welding.

[0063] S13, expanding the prefabricated steel pipe 1 with the expansion seam to obtain the carrier member 2 in the first state.

[0064] When the prefabricated steel pipe 1 with the expansion seam obtained in step S12 is expanded, the expansion is performed uniformly along the radial direction of the prefabricated steel pipe 1 to ensure that the radial cross-section of the prefabricated steel pipe 1 after expansion is still a perfect circle. The carrier member 2 after expansion is in the first state, and its structure is as follows: Figure 4 The expansion operation in this step is achieved by using an expansion device.

[0065] like Figure 5As shown, the expansion device includes: a first fixed seat 101, a plurality of expansion members 102 and a first driving mechanism; a receiving cavity is provided on the top of the first fixed seat 101; all the expansion members 102 are distributed on a first circumference; the expansion members 102 form a sliding connection with the bottom of the receiving cavity along the radial direction of the first circumference; the first driving mechanism is used to drive all the expansion members 102 to move away from or approach each other simultaneously along the radial direction of the first circumference.

[0066] Specifically, a cylindrical accommodating cavity is provided on the top of the first fixing seat 101, and the diameter of the accommodating cavity is equal to the first diameter; the expansion piece 102 includes an integrally formed first vertical portion and an inclined portion, and the first vertical portion is arranged perpendicular to the bottom of the accommodating cavity; the inclined portion is arranged at an end of the first vertical portion away from the bottom of the accommodating cavity, and the extension direction of the inclined portion forms a certain angle with the extension direction of the first vertical portion; the inclined portions of all the expansion pieces 102 together form a first conical space, and the opening of the first conical space faces upward; the number of the expansion pieces 102 is at least four, and in this embodiment, the number of the expansion pieces 102 is nine; the connection points of the first vertical portions of all the expansion pieces 102 and the first fixing seat 101 are evenly distributed on the first circumference. In this embodiment, the central angle corresponding to two adjacent expansion pieces 102 is 40°, and the expansion piece 102 is slidingly connected to the first fixing seat 101 along the radial direction of the first circumference.

[0067] The first driving mechanism is arranged above the first fixed seat 101, and includes a first telescopic driving device 103 and a first driving member 104; the first telescopic driving device 103 has a first telescopic driving end. In this embodiment, the first telescopic driving device 103 is a hydraulic cylinder, and the free end of the hydraulic cylinder piston rod is the first telescopic driving end; the first driving member 104 is a conical structure; the first telescopic driving end is fixedly connected to the large end of the first driving member 104, that is, the conical tip of the first driving member 104 faces downward; the central axis of the first driving member 104 passes through the center of the first circle; all the expansion members 102 are close to one end of the first driving member 104 to jointly enclose a first conical space matching the first driving member 104. Specifically, the first conical space has the same taper as the first driving member 104.

[0068] The method of using the above-mentioned expansion device to expand the prefabricated steel pipe with expansion seams is as follows: first, the prefabricated steel pipe with expansion seams is placed in the accommodating cavity of the first fixing seat 101, and is sleeved on the outside of the first vertical parts of all the expansion members 102; secondly, the first telescopic drive device 103 is started to drive the first drive member 104 to move downward, and the first drive member 104 gradually enters the first conical space and simultaneously applies an outward force to the inclined parts of each expansion member 102, so that each expansion member 102 moves away from each other along the radial direction of the first circumference at the same time, and at the same time, the first vertical part of each expansion member 102 applies a vertical force to the inner wall of the prefabricated steel pipe, so that the prefabricated steel pipe is gradually expanded. When the outer wall of the prefabricated steel pipe is tightly fitted with the inner wall of the accommodating cavity, the first telescopic drive device 103 is controlled to stop extending, that is, the expansion operation of the prefabricated steel pipe is completed, and at this time, the carrier member 2 in the first state is obtained.

[0069] In other embodiments of the present application, the method for obtaining the carrier component 2 can also be: first, obtain a prefabricated steel pipe with a set length, the diameter of the prefabricated steel pipe is the first diameter, and the other parameters of the prefabricated steel pipe are the same as those in step S11; secondly, perform two axial cuts on the wall of the prefabricated steel pipe to obtain a steel pipe with a notch, and the arc length corresponding to the notch is the difference in circumference between the outer circle of the first circular ring and the outer circle of the second circular ring; this method of obtaining the carrier component does not require the prefabricated steel pipe to be expanded.

[0070] S2. When the carrier component 2 is in the first state, the bushing inner core 3 is placed in the first cavity, which forms a vulcanization cavity together with the carrier component 2. Rubber material is injected into the vulcanization cavity and vulcanization forming is performed to obtain a first semi-finished product 4.

[0071] Specifically, it is also necessary to prepare the inner core 3 of the bushing in advance. The structure of the inner core 3 of the bushing is as follows: Figure 6 As shown, it is a hollow octagonal prism structure. Before the vulcanization step, the bushing core 3 and the carrier part 2 need to be subjected to surface treatments such as sandblasting and phosphating. After the treatment, glue is applied to the outer wall of the bushing core 3 and the inner wall of the carrier part 2 to facilitate its fixation with the vulcanized rubber; when the above preparations are completed, the carrier part 2 and the bushing core 3 are placed together in a vulcanization mold for vulcanization, wherein the bushing core 3 is located in the first cavity formed by the carrier part 2, and a vulcanization cavity is formed between the outer wall of the bushing core 3 and the inner wall of the carrier part 2; here, the structure of the vulcanization mold can be designed according to actual needs. The vulcanization mold in this embodiment is a common vulcanization mold in the prior art, and the vulcanization process of rubber is also a mature process in the prior art, which will not be repeated here. The vulcanized rubber, the carrier part 2 and the bushing core 3 together form a first semi-finished product 4 with a notch, and its structure is as shown in FIG. Figure 7 shown.

[0072] S3 . Compress the first semi-finished product 4 so that the carrier 2 switches from the first state to the second state, fix the first end and the second end, and obtain a second semi-finished product 5 .

[0073] When compressing the first semi-finished part 4 with a notch obtained in step S2, the carrier part 2 is uniformly compressed along the radial direction to ensure that the first end and the second end of the compressed carrier part 2 can fit tightly, and ensure that the radial cross-section of the compressed carrier part 2 is still a perfect circle, and the compressed carrier part 2 is in the second state; a cold welding process is used to weld the first end and the second end together. Cold welding technology is widely used, with good welding strength, less thermal damage to the parent body, and relatively small weld scars. It is very suitable for welding the skeleton of parts containing rubber. Therefore, in this step, a cold welding process is selected to weld the opening gap of the carrier part together. The main purpose of welding is to prevent the steel pipe edge from being misaligned during the reduction process, resulting in reduction failure. After welding, it can be ensured that the steel pipe shell is evenly stressed, and the design tolerance size can be achieved after reduction. The structure of the second semi-finished part 5 obtained in this step is as follows Figure 8 The compression operation in this step is achieved by using a compression device.

[0074] like Figure 9 As shown, the compression device includes: a second fixed seat 201, a plurality of compression members 202 and a second driving mechanism; the second fixed seat 201 has a first mounting surface; all the compression members 202 are distributed on a second circumference; the compression members 202 form a sliding connection with the first mounting surface along the radial direction of the second circumference; the second driving mechanism is used to drive all the compression members 202 to move away from or approach each other simultaneously along the radial direction of the second circumference.

[0075] Specifically, the second fixing seat 201 is a rectangular plate-shaped structure, and its top surface is the first mounting surface; the compression piece 202 includes a horizontal portion and a second vertical portion; the horizontal portion is slidably connected to the second fixing seat 201, and the second vertical portion is vertically provided on the side of the horizontal portion away from the second fixing seat 201; the number of the compression pieces 202 is at least four, and in this embodiment, the number of the compression pieces 202 is nine; the center points of the horizontal portions of all the compression pieces 202 are evenly distributed on the second circumference, and in this embodiment, the central angle corresponding to two adjacent compression pieces 202 is 40°; the horizontal portion of the compression piece 202 is slidably connected to the second fixing seat 201 along the radial direction of the first circumference, and when all the compression pieces 202 slide to the center position of the first circumference at the same time, the tops of the vertical portions of all the compression pieces 202 jointly form a conical structure, and the conical tips of the conical structures face upward.

[0076] The second driving mechanism is arranged above the second fixed seat 201, and includes a second telescopic driving device 203 and a second driving member 204; the second telescopic driving device 203 has a second telescopic driving end. In this embodiment, the second telescopic driving device 203 is a hydraulic cylinder, and the free end of the hydraulic cylinder piston rod is the second telescopic driving end; the second driving member 204 is a hollow cylindrical structure, one end of which is connected to the second telescopic driving end, and the other end has a second conical space. Specifically, a circle of frustum is provided on the inner wall of the lower end of the second driving member 204, so that the inner bottom end of the second driving member 204 forms a second conical space, and the large end of the second conical space is arranged away from the second telescopic driving end; all the compression members 202 away from the second fixed seat 201 together form a conical structure matching the second conical space. Specifically, the second conical space has the same taper as the conical structure formed by all the compression members 202.

[0077] The method of using the above-mentioned compression device to compress the first semi-finished product 4 is as follows: first, the first semi-finished product 4 is placed on the second fixed seat 201 and is located in the cylindrical space surrounded by each of the compression members 202; secondly, the second telescopic drive device 203 is started to drive the second drive member 204 to move downward, and the top of each compression member 202 gradually extends into the second conical space of the second drive member 204. The inner wall of the second drive member 204 simultaneously applies an inward force to each compression member 202, so that each compression member 202 moves simultaneously in the radial direction of the second circumference in the direction of approaching each other. At the same time, the second vertical portion of each compression member 202 applies a vertical force to the outer wall of the first semi-finished product 4, so that the carrier member 2 on the first semi-finished product 4 is gradually compressed. When the first end and the second end of the carrier member 2 are tightly fitted, the second telescopic drive device 203 is controlled to stop extending, that is, the compression operation of the first semi-finished product 4 is completed, and the carrier member 2 in the second state is obtained at this time.

[0078] Furthermore, the carrier member 2 also has a third state; when the carrier member 2 is in the third state, the shape of the cross-section formed radially on the carrier member 2 is a closed third circular ring, that is, the carrier member 2 in the third state is a closed hollow cylindrical structure; the outer circle diameter of the third circular ring is a third diameter; the third diameter is smaller than the second diameter.

[0079] Among them, the difference between the first diameter and the third diameter is greater than or equal to the target pre-compression amount; the target pre-compression amount is the pre-compression amount of the finished suspension bushing, the target pre-compression amount ranges from 4 to 7 mm, and the difference between the second diameter and the third diameter is 1 to 2 mm; in this embodiment, the target pre-compression amount is 5 mm; the first diameter is 106 mm, the third diameter is 100 mm, and the second diameter is 102 mm.

[0080] Furthermore, after obtaining the second semi-finished product 5 in step S3, the following steps are further included:

[0081] S4, grinding the second semi-finished product 5.

[0082] The second semi-finished part 5 obtained in step S3 adopts a cold welding process to achieve the closed fixation of the two ends of the carrier part 2, which makes the outer surface of the carrier part 2 not smooth enough and cannot meet the press-fitting requirements when the suspension bushing is subsequently installed. Therefore, the outer wall of the second semi-finished part 5 needs to be polished to remove the weld scars so that the outer wall surface of the second semi-finished part 5 is smooth, and the outer diameter tolerance of the second semi-finished part 5 after polishing meets the design requirements.

[0083] S5. Compress the second semi-finished product 5 so that the carrier 2 switches from the second state to the third state to obtain a finished product.

[0084] When compressing the second semi-finished product 5 after polishing in step S4, the carrier member 2 is uniformly compressed along its radial direction to ensure that the radial cross-section of the compressed carrier member remains a perfect circle. After compression, the carrier member 2 is in the third state. This step produces a finished suspension bushing. For ease of storage, the surface of the finished product is typically coated with rust-proof oil. The diameter reduction operation in this step is also performed using the compression device used in step S3. The structure and working principle of the compression device are not further described here.

[0085] The purpose of this step: the residual stress of the rubber and its skeleton is removed through the diameter reduction process, so that the suspension bushing can achieve better performance; the diameter reduction process can make the shell of the suspension bushing reach the designed tolerance size range, ensuring that the subsequent press-fitting is smooth, and the final interference fit is achieved after the press-fitting is completed, and the press-out force performance is guaranteed; the diameter reduction process can also provide a certain amount of pre-compression, thereby improving the performance of the suspension bushing.

[0086] The structure of the suspension bushing manufactured by the manufacturing method of this embodiment is as follows: Figure 10As shown, the suspension bushing includes a bushing shell 6, a bushing core 3 and a bushing rubber vulcanized therebetween; the bushing shell 6 is used to connect to the vehicle body, which is the fixed end; the bushing core 3 is used to connect to the engine, which is the moving end; the bushing rubber includes a main body 81 covering the outside of the bushing core 3, an upper limit portion 82 distributed above the main body 81 and fixedly vulcanized to the inner wall of the bushing shell 6, a left limit portion 83 distributed on the left side of the main body 81 and fixedly vulcanized to the inner wall of the bushing shell 6, a right limit portion 84 distributed on the right side of the main body 81 and fixedly vulcanized to the inner wall of the bushing shell 6, and a lower limit portion distributed on the lower side of the main body 81 and fixedly vulcanized to the inner wall of the bushing shell 6. 85; the lower sides of the main body 81 are fixed to the bushing shell 6 by a left main rib 86 and a right main rib 87 respectively; for the convenience of description, the distance between the main body 81 and the upper limit portion 82 is recorded as an upper gap, the distance between the main body 81 and the lower limit portion 85 is recorded as a lower gap, the distance between the main body 81 and the left limit portion 83 is recorded as a left gap, and the distance between the main body 81 and the right limit portion 84 is recorded as a right gap; the main body 81 and the upper limit portion 82 are pressed and deformed against each other, that is, the upper gap is a negative number, and the sum of the deformation amounts of the main body 81 and the upper limit portion 82 is equal to the target pre-compression amount. In this embodiment, the target pre-compression amount of the suspension bushing is 5 mm.

[0087] Before assembly, the finished suspension bushing of this embodiment has an upper clearance of -5mm and a lower clearance of 18mm. When the engine is assembled on the bushing inner core, due to the engine's own weight, the bushing rubber will be compressed by 6 to 8mm. Taking 6mm as an example, the upper clearance after assembly becomes 1mm and the lower clearance becomes 13mm. That is, the upper clearance is smaller after assembly, which can provide effective restriction, that is, it can effectively suppress the upward jumping of the engine, which is beneficial to vehicle vibration isolation and further beneficial to obtaining better NVH performance. In addition, traditional suspension bushings will produce creep within 1 to 2 weeks after being compressed by the engine's own weight at the initial stage of assembly (that is, slow permanent deformation occurs after being stressed, generally 1-2mm throughout its life). The suspension bushing of this embodiment shows a large pre-compression amount when leaving the factory. At this time, the actual component is equivalent to being in a compressed state. When it is assembled to the whole vehicle, the suspension bushing has actually gone through the creep process and the bushing rubber has reached a stable state. The suspension bushing of this embodiment avoids the suspension creep process, is more conducive to the suspension vibration isolation performance, and makes the performance of the whole vehicle more stable.

[0088] It should be noted that the position, shape and size of each part formed after the bushing rubber is vulcanized are determined by the vulcanization mold. Accordingly, the vulcanization mold has partitions corresponding to the upper gap, lower gap, left gap and right gap formed by the bushing rubber, wherein the size of the partition corresponding to the upper gap is 1mm. Assuming that the target pre-compression amount of the suspension bushing is 5mm, the target diameter (i.e. the third diameter) is 100mm, and the target reduction size is 2mm, the value of the first diameter is: the sum of the target diameter, target pre-compression amount and target reduction size minus the size of the partition corresponding to the upper gap of the vulcanization mold, i.e. the first diameter is 106mm, and the second diameter is the first diameter minus the target reduction size, i.e. the second diameter is 104mm.

[0089] Since the carrier has a gap during vulcanization, that is, the diameter of the carrier during vulcanization and before shrinkage is different, in the process of compressing the carrier to close the gap, the various parts of the bushing rubber will have a certain displacement change, so it is necessary to make a slight dimensional correction to the vulcanization mold. Since rubber itself has good compression performance, the dimensional tolerance required after its mold forming is generally set relatively large (generally ±1mm), so the places with small dimensional changes are negligible. The specific mold correction is: the split angle formed by the left main rib and the right main rib; assuming that the split angle formed by the left main rib and the right main rib of the suspended bushing finished part is θ2, according to the design, the value of θ2 is 60°, and the split angle formed by the left main rib and the right main rib of the first semi-finished part after vulcanization is recorded as θ1, then:

[0090]

[0091] Wherein, d1 is the first diameter, d2 is the second diameter, and θ1 is calculated to be 74°.

[0092] According to the value of θ1 obtained by the above calculation, the parts corresponding to the left and right main reinforcements in the vulcanization mold are corrected, and the remaining parts can be adjusted accordingly. It should be noted that during vulcanization, the notch of the carrier part should correspond to the part between the corresponding lower limit part and the right main reinforcement in the vulcanization mold.

[0093] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of the present invention, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A method for manufacturing a suspension bushing, characterized in that: The method comprises the following steps: Obtain a carrier member; the carrier member has a first end and a second end; the first end and the second end are bent in a direction approaching each other to form a first cavity; the carrier member has a first state and a second state, in the first state, the first end and the second end are separated from each other, and in the second state, the first end and the second end are closely attached to each other; the carrier member also has a third state; When the carrier is in the first state, the bushing inner core is placed in the first cavity, and the bushing inner core and the carrier together form a vulcanization cavity. The rubber material is injected into the vulcanization cavity and vulcanized to obtain a first semi-finished product. Compressing the first semi-finished product so that the carrier component switches from the first state to the second state, fixing the first end and the second end to obtain a second semi-finished product; compressing the second semi-finished product so that the carrier part switches from the second state to the third state to obtain a finished product; Wherein, when the carrier is in the first state, the cross section formed on the carrier along the radial direction is in the shape of a first circular ring with an opening; the outer diameter of the first circular ring is a first diameter; When the carrier is in the second state, the cross section formed along the radial direction of the carrier is in the shape of a closed second circular ring; the outer diameter of the second circular ring is a second diameter; and the second diameter is smaller than the first diameter; When the carrier is in the third state, the cross section formed along the radial direction of the carrier is in the shape of a closed third circular ring; the outer diameter of the third circular ring is a third diameter; and the third diameter is smaller than the second diameter; The difference between the first diameter and the third diameter is greater than or equal to a target pre-compression amount; the target pre-compression amount is the pre-compression amount of the finished suspension bushing.

2. The method for manufacturing a suspension bushing according to claim 1, wherein: On a side of the opening relatively far from the center of the first circular ring, a line connecting the first end and the second end is a chord of the outer circle of the first circular ring.

3. The method for manufacturing a suspension bushing according to claim 2, wherein: The step of obtaining the carrier member comprises: Obtaining a prefabricated steel pipe with a set length; the diameter of the prefabricated steel pipe is the second diameter; An expansion seam is provided in the axial direction on the wall of the prefabricated steel pipe; The prefabricated steel pipe with the expansion seam is expanded to obtain the carrier member in the first state.

4. The method for manufacturing a suspension bushing according to claim 3, wherein: When expanding the prefabricated steel pipe with the expansion seam to obtain the carrier member in the first state, an expansion device is used; The expansion device comprises: A first fixing seat, wherein a receiving cavity is provided on the top of the first fixing seat; A plurality of expansion members, all of which are distributed on a first circumference; the expansion members are in sliding connection with the bottom of the accommodating cavity in a radial direction along the first circumference; A first driving mechanism is used to drive all the expansion members to move away from or toward each other simultaneously along the radial direction of the first circumference.

5. The method for manufacturing a suspension bushing according to claim 4, wherein: The first driving mechanism includes a first telescopic driving device and a first driving member; the first telescopic driving device has a first telescopic driving end; the first driving member is a conical structure; the first telescopic driving end is fixedly connected to the large end of the first driving member; the central axis of the first driving member passes through the center of the first circle; all the expansion members are close to one end of the first driving member to jointly enclose a first conical space that matches the first driving member.

6. The method for manufacturing a suspension bushing according to claim 2, wherein: said compressing said first semi-finished product, said carrier member switching from said first state to said second state, using a compression device; The compression device comprises: a second fixing seat, the second fixing seat having a first mounting surface; A plurality of compression members, all of which are distributed on a second circumference; the compression members and the first mounting surface form a sliding connection along the radial direction of the second circumference; The second driving mechanism is used to drive all the compression members to move away from or approach each other simultaneously along the radial direction of the second circumference.

7. The method for manufacturing a suspension bushing according to claim 6, wherein: The second driving mechanism includes a second telescopic driving device and a second driving member; the second telescopic driving device has a second telescopic driving end; one end of the second driving member is connected to the second telescopic driving end, and the other end has a second conical space; the large end of the second conical space is arranged away from the second telescopic driving end; all the compression members together form a conical structure that matches the second conical space with one end away from the second fixed seat.

8. A suspension bushing manufactured by the method for manufacturing a suspension bushing according to any one of claims 1 to 7, characterized in that: The suspension bushing includes a bushing shell, a bushing core and a bushing rubber vulcanized between the two; the bushing shell is used to connect to the vehicle body; the bushing core is used to connect to the engine; the bushing rubber includes a main body covering the outside of the bushing core, and an upper limit portion distributed above the main body and vulcanized and fixed to the inner wall of the bushing shell; the main body and the upper limit portion are pressed and deformed against each other, and the sum of their deformations is equal to the target pre-compression amount.

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