A hydraulic bushing for a commercial vehicle cab

Abstract

The present invention relates to a hydraulic bushing for a commercial vehicle cab, comprising an outer sleeve and an inner sleeve assembly, wherein the inner sleeve assembly comprises a rubber main spring and an inner tube, wherein the rubber main spring is composed of an upper main spring, a lower main spring and an intermediate main spring, wherein the intermediate main spring is composed of a middle main spring and a side main spring, wherein the middle main spring is mounted on the inner tube, and a limit plate is arranged between the middle main spring and the inner tube, wherein the two ends of the inner tube extend out of the upper main spring and the lower main spring respectively, wherein the inner sleeve assembly is mounted in the outer sleeve by interference fit, wherein the outer sleeve is separated into an upper chamber and a lower chamber by the rubber main spring, wherein a flow channel connecting the upper chamber and the lower chamber is opened on the side main spring, wherein the upper chamber, the lower chamber and the flow channel are filled with silicone oil. The present invention solves the problem of insufficient vibration isolation due to excessive suspension stiffness at high frequency and small amplitude, and simultaneously solves the problem of excessive up and down displacement of the suspension, excessive up and down bouncing of the cab, and unacceptable bumpy feeling due to excessively small suspension damping at low frequency and large amplitude.

Description

Technical Field

[0001] The invention relates to a hydraulic bushing for a vehicle cab, in particular to a hydraulic bushing for a commercial vehicle cab. Background Art

[0002] The cab weight of existing commercial vehicles (such as Chenglong and Balong) is 600-1000Kg, and the cab is mostly connected to the body at four points, with the first two suspensions being rubber suspensions and the last two suspensions being air springs. The cab and the four-point suspension form a spring system. The excitation force of the powertrain and the road surface will be transmitted to the cab through the four-point suspension, and then to the cab occupants. Since the excitation source consists of two aspects, and the excitation frequency and amplitude are quite different, it is difficult for the traditional pure rubber suspension to take into account both aspects of excitation.

[0003] The hydraulic mounts currently on the market are generally hydraulic mounts using ethylene glycol liquid, which has low liquid viscosity and contains inertial channels, decoupling membranes, spoilers, membranes and other parts. The product structure is relatively complex, and the damping provided is not large enough, the load-bearing capacity is light, and the reliability is uncertain, making it unsuitable for commercial vehicle cab suspensions.

[0004] The existing technologies for cab suspension have the following main shortcomings: 1. The vibration isolation of the cab suspension is poor, and the steering wheel and seat of the cab vibrate greatly and make a lot of noise; 2. The damping provided by the cab suspension is small, the cab bounces up and down greatly, and the bumpy feeling is strong; 3. The existing hydraulic suspension has a small load-bearing capacity and low reliability; 4. The existing hydraulic suspension has a complex structure and high cost; 5. The existing hydraulic suspension has a narrow frequency band and low damping; 6. The existing hydraulic suspension liquid has a low viscosity and a small inertial force.

[0005] Chinese patent CN200910067531.1 discloses a hydraulic suspension for a car cab, which is mainly composed of upper and lower liquid chambers, a shell, a buffer limit block, an inertia channel body, a bottom membrane, a rubber main spring, a metal frame and a base. This patent also has the following shortcomings: 1. The inertia channel is formed by borrowing other accessory parts, not by the rubber main spring itself, and a spoiler structure is also provided, which is complex in structure; 2. It is filled with ethylene glycol liquid with very low viscosity, and the inertia force is small; 3. This patent does not give specific performance parameters, and generally its hysteresis angle or damping frequency band is relatively narrow, and the excitation amplitude is small; 4. It can be applied to the cab of passenger cars, but not suitable for use on commercial vehicles. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a hydraulic bushing for a commercial vehicle cab with a simple structure, low stiffness and high damping, which solves the problem of insufficient vibration isolation due to excessive suspension stiffness during high frequency and small amplitude, and at the same time solves the problem of excessive up and down displacement of the suspension, excessive up and down jumping of the cab and unacceptable bumpy feeling due to excessive suspension damping during low frequency and large amplitude.

[0007] The technical solution to solve the above technical problems is: a commercial vehicle cab hydraulic bushing, including an outer sleeve and an inner sleeve assembly, the inner sleeve assembly includes a rubber main spring and an inner tube, the rubber main spring is composed of an upper main spring, a lower main spring and an intermediate main spring connected between the upper main spring and the lower main spring, the intermediate main spring is composed of a middle main spring and side main springs integrally formed on both sides of the middle main spring, the middle main spring is installed on the inner tube, and a limit plate is also arranged between the middle main spring and the inner tube, and the two ends of the inner tube extend out of the upper main spring and the lower main spring respectively, the inner sleeve assembly is installed in the outer sleeve by interference fit, the outer sleeve is divided into an upper chamber and a lower chamber by the rubber main spring, a flow channel connecting the upper chamber and the lower chamber is opened on the side main spring, the upper chamber, the lower chamber and the flow channel are filled with silicone oil, and a filling hole is arranged on the outer sleeve, and the filling hole is closed by a rivet.

[0008] A metal piece is arranged on the outer side of the rubber main spring, and a reducing slit is opened on the metal piece.

[0009] The inner wall of the outer sleeve is also provided with a circle of sealing ribs, and the rubber main spring and the sealing ribs are sealed and connected by a metal piece.

[0010] The upper main spring is marked with an installation mark and a static load deviation line.

[0011] The outer edge of the middle main spring is also provided with buffer and avoidance ribs.

[0012] The viscosity of the silicone oil is 10,000-15,000 cst.

[0013] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0014] 1. After the structure of the present invention is improved, it is filled with high-viscosity silicone oil and outputs a smaller stiffness, which solves the problem of insufficient suspension vibration isolation due to excessive suspension stiffness at high frequencies (engine excitation or high-speed road excitation) and small amplitudes. At the same time, it solves the problem of excessive up and down displacement of the suspension, excessive up and down bouncing of the cab, and unacceptable bumpy feeling due to too small suspension damping at low frequencies (rough road excitation) and large amplitudes.

[0015] 2. The loss angle of general rubber suspension is only about 10°, and the damping coefficient is less than 1N*S / MM. However, the loss angle of the present invention can reach more than 40°, and the frequency can be controlled to be adjusted within 2-50Hz, which is more suitable for commercial vehicles.

[0016] 3. The structure of the present invention is relatively simple, not as complicated as the traditional hydraulic mount, with low risk of failure and low cost.

[0017] The technical features of a hydraulic bushing for a commercial vehicle cab of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 : A three-dimensional diagram of the hydraulic bushing in the cab of a commercial vehicle of the present invention.

[0019] Figure 2 : Front view of the hydraulic bushing of the commercial vehicle cab of the present invention.

[0020] Figure 3 : Figure 2 AA section view.

[0021] Figure 4 : Figure 3 BB cross-sectional view.

[0022] Figure 5 : The inner sleeve of the present invention is generally three-dimensional.

[0023] Figure 6 : The inner sleeve assembly front view of the present invention.

[0024] Figure 7 : A top view of the inner sleeve assembly of the present invention.

[0025] Figure 8 : A three-dimensional diagram of the outer cover of the present invention.

[0026] Fig. 9 : Front view of the outer cover of the present invention.

[0027] Fig.10 : Fig. 9 CC cross-sectional view.

[0028] In the figure: 1-outer sleeve, 2-sealing rib, 3-metal parts, 4-rubber main spring, 41-upper main spring, 42-middle main spring, 421-middle main spring, 422-side main spring, 43-lower main spring, 5-inner tube, 6-flow channel, 7-limiting plate, 8-buffer and avoidance rib, 9-rivet, 10-installation mark, 11-reduction seam, 12-static load deviation line.

[0029] P1 represents the upper chamber, and P2 represents the lower chamber. DETAILED DESCRIPTION

[0030] Embodiment 1: A hydraulic bushing for a commercial vehicle cab, such as Figure 1-Figure 10As shown, it includes an outer sleeve 1 and an inner sleeve assembly, and the inner sleeve assembly includes a rubber main spring 4 and an inner tube 5. The rubber main spring is composed of an upper main spring 41, a lower main spring 43 and an intermediate main spring 42 connected between the upper main spring and the lower main spring. The intermediate main spring 42 is composed of a middle main spring 421 and side main springs 422 integrally formed on both sides of the middle main spring. The middle main spring is installed on the inner tube, and a limit plate 7 is also arranged between the middle main spring and the inner tube. The two ends of the inner tube extend out of the upper main spring and the lower main spring respectively. The inner sleeve assembly is installed in the outer sleeve by interference fit, and the outer sleeve is separated by the rubber main spring to form an upper chamber P1 and a lower chamber P2. A flow channel 6 (4 symmetrically arranged) connecting the upper chamber and the lower chamber is opened on the side main spring, and the upper chamber, the lower chamber and the flow channel are filled with silicone oil. The outer sleeve is provided with a liquid filling hole, and the liquid filling hole is closed by a rivet 9.

[0031] In this embodiment, a metal part 3 (i.e., an outer iron part, which serves as a connection) is provided on the outer side surface of the rubber main spring 4, and a reducing seam 11 is provided on the metal part. The reducing seam is provided in order to better perform the reducing process and release the shrinkage stress inside the rubber. A circle of sealing ribs 2 is also provided on the inner wall of the outer sleeve, and the rubber main spring and the sealing ribs are sealed and connected via the metal part 3. An installation mark 10 and a static load deviation line 12 are marked on the upper main spring. The static load deviation line is provided so that the inner and outer tubes are in a concentric state after the product is installed on the vehicle. Buffering and avoidance ribs 8 are also provided on the outer edge of the middle main spring. The buffering and avoidance ribs are used to better reflect nonlinear limiting and avoid collision with rivets.

[0032] The embodiment of the present invention is mainly composed of a rubber main spring and liquid. There are upper and lower chambers inside the hydraulic bushing, which are connected through a channel. The liquid fills the entire cavity and channel. When the inner and outer tubes of the hydraulic bushing move relative to each other, the liquid will move in the channel to form resistance, thereby generating a large damping and hysteresis angle.

[0033] The present invention outputs a smaller stiffness; in a certain frequency range, it outputs a larger damping and hysteresis angle; it improves the phenomenon of poor vibration isolation and strong bumpy feeling of commercial vehicles; the liquid viscosity is 10,000-15,000 cst; the product has a working direction stiffness of 160-270 N / mm, a loss angle of 40-50°, a corresponding frequency of 4.75 Hz, and a damping coefficient of 6-7 N.S / mm; the assembly is press-fitted and then riveted to seal the edges, and the pressing force can be greater than 10,000 N; vacuum dry filling is used for liquid filling; the liquid filling hole is closed with a core-pulling rivet; the inner and outer sleeves are press-fitted with interference fit and rubber sealing.

Claims

1. A hydraulic bushing for a commercial vehicle cab, characterized in that: The invention comprises an outer sleeve (1) and an inner sleeve assembly, wherein the inner sleeve assembly comprises a rubber main spring (4) and an inner tube (5), wherein the rubber main spring comprises an upper main spring (41), a lower main spring (43) and an intermediate main spring (42) connected between the upper main spring and the lower main spring, wherein the intermediate main spring (42) comprises a middle main spring (421) and side main springs (422) integrally formed on both sides of the middle main spring, wherein the middle main spring is mounted on the inner tube, and the middle main spring A limit plate (7) is also provided between the inner tube and the inner tube. The two ends of the inner tube extend out of the upper main spring and the lower main spring respectively. The inner sleeve assembly is installed in the outer sleeve by interference fit. The outer sleeve is separated by the rubber main spring to form an upper chamber (P1) and a lower chamber (P2). A flow channel (6) connecting the upper chamber and the lower chamber is opened on the side main spring. The upper chamber, the lower chamber and the flow channel are filled with silicone oil. The outer sleeve is provided with a liquid filling hole, which is closed by a rivet (9).

2. A commercial vehicle cab hydraulic bushing according to claim 1, characterized in that: A metal piece (3) is provided on the outer side surface of the rubber main spring (4), and a reducing slit (11) is provided on the metal piece.

3. A commercial vehicle cab hydraulic bushing according to claim 2, characterized in that: The inner wall of the outer sleeve is also provided with a circle of sealing ribs (2), and the rubber main spring and the sealing ribs are sealed and connected via a metal piece (3).

4. A commercial vehicle cab hydraulic bushing according to any one of claims 1 to 3, characterized in that: The upper main spring is marked with an installation mark (10) and a static load deflection line (12).

5. A commercial vehicle cab hydraulic bushing according to any one of claims 1 to 3, characterized in that: The outer edge of the middle main spring is also provided with a buffer and avoidance rib (8).

6. A commercial vehicle cab hydraulic bushing according to any one of claims 1 to 3, characterized in that: The viscosity of the silicone oil is 10,000-15,000 cst.

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