CN116146678A

CN116146678A - Double-spring type hydraulic tensioner

Info

Publication number: CN116146678A
Application number: CN202310179927.5A
Authority: CN
Inventors: 佟艺波; 包翔; 陈腾霄; 张柏成
Original assignee: Hangzhou Donghua Automobile Power Technology Co ltd
Current assignee: Hangzhou Donghua Automobile Power Technology Co ltd
Priority date: 2023-02-17
Filing date: 2023-02-17
Publication date: 2023-05-23

Abstract

The invention discloses a double-spring type hydraulic tensioner, which comprises a shell, a plunger spring, a one-way valve and a pressure relief valve, wherein the plunger spring is arranged on the shell; the top of the plunger is provided with a spring buffer compensation mechanism, the pressure release valve is assembled at the top of the inner cavity of the plunger, the plunger spring is sleeved outside the pressure release valve, and the upper end part of the plunger spring is abutted with the lower end surface of the pressure release valve; the top end of the plunger is provided with a buffer mechanism, and the plunger is communicated with the buffer mechanism through an oil outlet; the buffer mechanism is in contact with the vibrating object. The variable pitch compression spring is used for replacing a common spring in the hydraulic cavity, and meanwhile, through the cooperation of the variable pitch compression spring and the plunger top buffer mechanism, not only can the spring force required by the system be provided, but also useless friction work of the system can be reduced, and the situation that the plunger cannot be ejected out in time due to negative pressure to cause abnormal sound of the engine can be avoided; through the use of the large-flow check valve, damping force can be rapidly formed, and the buffer mechanism and the tensioner body provide better tensioning force for the vibrating object.

Description

Double-spring type hydraulic tensioner

Technical Field

The invention provides a hydraulic tensioner, and particularly relates to a double-spring type hydraulic tensioner.

Background

Conventionally, hydraulic tensioners have been widely used for transmission media such as timing chains for transmitting rotation between a crankshaft and a camshaft of a vehicle engine in order to suppress vibrations generated during the running of the transmission media and to maintain an appropriate tension.

The conventional hydraulic tensioner includes a housing having a cylindrical hole, a plunger slidable in the cylindrical hole and having one end protruding from an opening, and a plunger spring pressing the plunger in a protruding direction, the housing and the plunger together constituting a high-pressure oil reservoir, and a check valve mechanism including a metal cylinder is installed in the cylindrical hole of the housing so that oil can enter the high-pressure oil reservoir to form a damping to play a role in adjusting a tensioning force of an engine chain.

When the hydraulic tensioner adjusts the tensioning force of the vibrating object (chain/rail), the plunger end in the hydraulic tensioner contacts the vibrating object (chain/rail) to provide the tensioning force. Meanwhile, in a timing system of the engine, the chain stretches along with the service time, and the plunger stretches along with the service time, so that the spring force is reduced; and can provide interference tensioning force and energy consumption more in the tensioning function of tensioning ware, also can cause the plunger of tensioning ware and vibration object (chain/guide rail) to appear not in time popping out the condition that appears abnormal sound because of the cavity negative pressure, lead to the engine to appear abnormal sound problem.

Disclosure of Invention

To sum up, in order to optimize the deficiencies in the prior art, a dual spring hydraulic tensioner is proposed.

In order to achieve the above object, the present invention is realized by the following means: the invention relates to a double-spring type hydraulic tensioner, which comprises a shell, wherein a hydraulic cavity is arranged in the shell, an oil inlet channel is arranged at the bottom of the hydraulic cavity, and the double-spring type hydraulic tensioner further comprises: the plunger is telescopically arranged in the hydraulic cavity and is provided with a cavity with a downward opening; the plunger spring is arranged in the cavity of the plunger, and is a variable-pitch compression spring; the one-way valve is arranged at the bottom of the hydraulic cavity, the input end of the one-way valve is communicated with the oil inlet channel, the output end of the one-way valve is contacted with one end of the plunger spring, and the one-way valve is a high-flow one-way valve; the top end of the cavity of the plunger is provided with a pressure relief valve, the plunger spring is sleeved outside the pressure relief valve, and the upper end part of the plunger spring is abutted with the lower end surface of the pressure relief valve; the top end of the plunger is provided with a buffer mechanism, and the plunger is communicated with the buffer mechanism through an oil outlet; and the buffer mechanism is in contact with the vibrating object.

Further, the buffer mechanism comprises an extension part integrally connected to the top end of the plunger, an accommodating cavity with an upward opening is arranged in the extension part, and a secondary spring and a plug are arranged in the accommodating cavity at the same time, wherein one end of the secondary spring is abutted to the bottom of the accommodating cavity, and the other end of the secondary spring is abutted to the bottom of the plug; and the plug is in contact with the vibrating object.

Further, hold the oil outlet intercommunication on chamber and the plunger, simultaneously hold the upper end in chamber and be shrink form and hold the chamber in the shape of falling T, and the top is then installed in holding the chamber in the cooperation, wherein, the outside of top back of the body lower extreme is equipped with annular draw-in groove, and the cover is equipped with the secondary jump ring on this annular draw-in groove, and the outside of secondary jump ring then with hold the inner wall joint in chamber.

Further, a clamp spring is sleeved on the plunger, and a clamping groove matched with the clamp spring is formed in the inner wall of the hydraulic cavity.

Further, the plunger spring is a variable pitch compression spring.

Further, the pressure release valve comprises a valve cap, a base, a spring and a steel ball, and an oil duct is arranged on the valve cap.

Compared with the prior art, the invention has the following beneficial effects: the variable pitch compression spring is used for replacing a common spring in the hydraulic cavity, and meanwhile, through the cooperation of the variable pitch compression spring and the plunger top buffer mechanism, not only can the spring force required by the system be provided, but also useless friction work of the system can be reduced, and the situation that the plunger cannot be ejected out in time due to negative pressure to cause abnormal sound of the engine can be avoided; through the use of the large-flow check valve, damping force can be rapidly formed, and the buffer mechanism and the tensioner body provide better tensioning force for the vibrating object.

Drawings

Fig. 1 is a schematic cross-sectional structure of the present application.

Fig. 2 is a schematic view of a tensioner and rail contact profile and a partial enlarged view of the present application.

Fig. 3 is a schematic front view of the practical application of the present application.

Fig. 4 is a schematic cross-sectional structure of the relief valve and a top view of the relief valve in the present application.

FIG. 5 is a graph showing the comparison of the oil pressure-flow curves of the check valve used in the present application and the check valve used in the conventional application.

FIG. 6 is a graphical representation of the hysteresis curves of the present application versus a conventional tensioner.

Fig. 7 is a comparison of the spring (variable pitch compression spring) applied in the hydraulic chamber of the present application with the normal spring chain deformation-spring force.

Reference numerals: the hydraulic valve comprises a shell 10, a hydraulic cavity 11, a one-way valve 12, a plunger spring 13, an oil inlet channel 14, a clamping groove 15 and a clamping spring 16;

plunger 20, cavity 21, relief valve 22, oil outlet 23, valve cap 220, base 221, spring 222, steel ball 223, oil duct 220a;

the buffer mechanism 30, the extension part 30a, the accommodating cavity 31, the plug 32, the annular clamping groove 32a, the secondary clamping spring 32b and the secondary spring 33; the object 40 is vibrated.

Detailed Description

The invention is further described below with reference to the drawings and specific examples. One of ordinary skill in the art will be able to implement the invention based on these descriptions. In addition, the embodiments of the present invention referred to in the following description are typically only some, but not all, embodiments of the present invention. Thus, all other embodiments, which can be made by one of ordinary skill in the art without undue burden, based on the embodiments of the invention are intended to be within the scope of the invention.

As an embodiment of the present invention, the present invention is a dual spring hydraulic tensioner, which includes a housing 10, a plunger 20, a plunger spring 13, a check valve 12, a relief valve 22, and a buffer mechanism 30, as described below with reference to fig. 1, 2, and 3.

Referring specifically to fig. 1, a hydraulic cavity 11 is provided in a housing 10, an oil inlet channel 14 is provided at the bottom of the hydraulic cavity 11, a plunger 20 is telescopically installed in the hydraulic cavity 11, and the plunger 20 is provided with a cavity 21 with a downward opening; the plunger spring 13 is arranged in the cavity 21 of the plunger 20, and is a variable pitch compression spring; the one-way valve 12 is arranged at the bottom of the hydraulic cavity 11, the input end of the one-way valve 12 is communicated with the oil inlet channel 14, the output end of the one-way valve 12 is contacted with one end of the plunger spring 13, and the one-way valve is a high-flow one-way valve; wherein, the top end of the cavity 21 of the plunger 20 is provided with a pressure release valve 22, the plunger spring 13 is sleeved outside the pressure release valve 22, and the upper end part of the plunger spring 13 is abutted with the lower end surface of the pressure release valve 22; the top end of the plunger 20 is provided with a buffer mechanism 30, and the plunger 20 is communicated with the buffer mechanism 30 through an oil outlet 23; while the buffer mechanism 30 is in contact with the vibrating object 40.

Referring to fig. 1, in this arrangement, the buffer mechanism 30 includes an extension portion 30a integrally connected to the top end of the plunger 20, wherein an upwardly open accommodating cavity 31 is provided in the extension portion 30a, and a secondary spring 33 and a plug 32 are installed in the accommodating cavity 31, wherein one end of the secondary spring 33 abuts against the bottom of the accommodating cavity 30a, and the other end of the secondary spring 33 abuts against the bottom of the plug 32; and the plug 32 is in contact with the vibrating object 40.

In the above arrangement, the contact surface between the vibrating object 40 and the plug 32 in the buffer mechanism 30 may be provided with a caulking groove matched with the plug 32, and the plug 32 may be movable in the caulking groove, so that the whole tensioner may provide a good tensioning force for the vibrating object 40.

The top of the plunger is provided with a containing cavity 31 which can contain the spring, and a plug is arranged in the cavity to form a buffer mechanism, if the plunger 20 cannot be ejected out in time due to negative pressure, the secondary spring 33 at the top of the plunger can complement the elasticity, so that the problem of overlarge abnormal sound can not occur when the engine moves.

Referring to fig. 1, the accommodating cavity 31 is communicated with the oil outlet 23 on the plunger 20, and meanwhile, the upper end of the accommodating cavity 31 is in a contracted shape and forms an inverted T-shaped accommodating cavity, and the plug 32 is mounted in the accommodating cavity 31 in a matched manner, wherein an annular clamping groove 32a is arranged outside the lower end of the plug 32, a secondary clamping spring 32b is sleeved on the annular clamping groove 32a, and the outer side of the secondary clamping spring 32b is clamped with the inner wall of the accommodating cavity 31.

In this embodiment, the top 32 may be cylindrical and the upper end of the top 32 is abutted against the vibrating object, while the lower end of the top 32 is inserted into the accommodating cavity 31, and the top 32 is inserted into the accommodating cavity 31, so that the secondary clamp spring 32b is installed, and the buffer mechanism is engaged with the upper end of the accommodating cavity 31 during use, so as to limit the top 32, thereby ensuring the spring force provided by the buffer mechanism for the system.

In the above embodiment, referring specifically to fig. 4, the pressure relief valve 22 is composed of a valve cap 220, a base 221, a spring 222 and a steel ball 223, and the valve cap 220 is provided with an oil passage 220a, so that the flow rate can be adjusted under different oil pressures to balance the tensioning operation state during low-speed and high-speed operation of the engine; when the hydraulic tensioner provides tensioning force for the vibrating object, hydraulic oil in the hydraulic cavity is sprayed out from the oil outlet under the action of the pressure relief valve, components in the buffer mechanism 30 are lubricated through the oil outlet 23, oil flows out from the oil duct when the pressure relief valve is at low oil pressure, the spring 222 is compressed when the pressure relief valve is at high pressure, and the oil flows out from a gap between the base 221 and the steel ball 223, so that the oil outlet capacity of high oil pressure is greatly enhanced, the tensioner is fast tightened, and friction work on a chain is reduced.

Also in the above arrangement, the spring 222 may be a small force spring to reduce friction work and save cost.

In the above embodiment, referring specifically to fig. 5 and the following chart, in this arrangement, the check valve 12 uses a high-flow check valve, the pressure in the oil inlet chamber of the tensioner is low, at the same low oil pressure, since the opening flow rate of the high-flow check valve is far higher than that of the normal check valve, and under the same chamber, the filling speed of the dual-spring hydraulic tensioner is far higher than that of the normal tensioner (the initial difference value is d), and by matching the variable-pitch compression spring with the plunger end buffer mechanism, the response speed of the hydraulic tensioner in this application is far higher than that of the normal tensioner, so that the hydraulic tensioner can quickly establish the oil pressure in the hydraulic chamber, and can quickly provide the tensioning force for the vibrating object 40, so as to reduce the noise at the initial start of the engine.

	0.1MPA	0.2MPA	0.5MA	1MPA
					Large-flow check valve (HFCV)	358ml/min	527mml/min	856ml/min	1261ml/min
Common one-way valve	120ml/min	238ml/min	621ml/min	1240ml/min

In the above embodiment, as shown in fig. 1, 6 and 7, in this arrangement, the plunger spring 13 is a variable pitch compression spring, and a variable pitch compression spring with a small wire diameter is used, and the spring coefficient is small when the wire diameter is small, and the displacement-spring force curve of the spring is changed by changing the pitch, so that the spring force difference of the tensioner is smaller in the two states of initial and chain extension, and the tensioning function is more reliable and stable.

Specifically (refer to the following chart): the spring coefficient is variable, and the pitch spring has sufficient spring force after the chain is stretched, so that the tensioner has sufficient spring force in the early stage to the later stage of service life.

	Chain unextended spring force/N	Chain elongation 0.5% spring force/N	Spring force difference/N
				Pitch-variable press-fitting spring	74.16	63.48	10.68
Common press-fitting spring	85.59	58.46	27.13

In the above arrangement, referring to fig. 6, the present application has a hysteresis curve (curve of the extension amount of the tensioner versus the damping force) that is more sensitive in the compression stroke of the plunger spring (variable pitch compression spring) than the conventional tensioner; meanwhile, the high-flow check valve is used for quickly feeding oil, the plunger is ejected out more quickly, the tensioning force is provided more quickly, and the extension time of the plunger is shortened; meanwhile, a pressure release valve is used, so that oil is discharged more quickly at high pressure, and a plunger is compressed more quickly, so that the contraction time is shortened; through the cooperation of variable pitch compression spring, relief valve and buffer gear for the tensioning ware of this application has more nimble hysteresis curve, realizes that the plunger is faster tightens up and pops out and faster system response.

In the above arrangement, the plunger 20 is sleeved with the clamp spring 16 in combination with fig. 1, and the inner wall of the hydraulic cavity 11 is provided with the clamping groove 15 matched with the clamp spring 16.

The present invention is not limited to the above-mentioned embodiments, and any person skilled in the art, based on the technical solution of the present invention and the inventive concept thereof, can be replaced or changed within the scope of the present invention.

Claims

1. The utility model provides a double spring formula hydraulic tensioner, includes casing (10), is equipped with hydraulic pressure cavity (11) in this casing (10), the bottom of hydraulic pressure cavity (11) is equipped with oil feed passageway (14), its characterized in that still includes:

the plunger (20) is telescopically arranged in the hydraulic cavity (11), and the plunger (20) is provided with a cavity (21) with a downward opening;

the plunger spring (13) is arranged in the cavity (21) of the plunger (20), and the plunger spring is a variable pitch compression spring;

the one-way valve (12) is arranged at the bottom of the hydraulic cavity (11), the input end of the one-way valve (12) is communicated with the oil inlet channel (14), the output end of the one-way valve (12) is contacted with one end of the plunger spring (13), and the one-way valve is a high-flow one-way valve; the top end of a cavity (21) of the plunger (20) is provided with a pressure relief valve (22), the plunger spring (13) is sleeved outside the pressure relief valve (22), and the upper end part of the plunger spring (13) is abutted with the lower end surface of the pressure relief valve (22); the top end of the plunger (20) is provided with a buffer mechanism (30), and the plunger (20) is communicated with the buffer mechanism (30) through an oil outlet (23); and the buffer mechanism (30) is in contact with the vibrating object (40).

2. A dual spring hydraulic tensioner according to claim 1, wherein the buffer mechanism (30) comprises an extension part (30 a) integrally connected to the top end of the plunger (20), the extension part (30 a) is provided with an upward opening accommodating cavity (31), and a secondary spring (33) and a plug (32) are installed in the accommodating cavity (31), wherein one end of the secondary spring (33) is abutted to the bottom of the accommodating cavity (30 a), and the other end of the secondary spring (33) is abutted to the bottom of the plug (32); and the plug (32) is in contact with the vibrating object (40).

3. The dual spring hydraulic tensioner of claim 2, wherein the accommodating cavity (31) is communicated with the oil outlet (23) on the plunger (20), the upper end of the accommodating cavity (31) is in a contracted shape and forms an inverted T-shaped accommodating cavity, the plug (32) is mounted in the accommodating cavity (31) in a matched manner, an annular clamping groove (32 a) is formed in the outer portion of the lower end of the plug (32), a secondary clamping spring (32 b) is sleeved on the annular clamping groove (32 a), and the outer side of the secondary clamping spring (32 b) is clamped with the inner wall of the accommodating cavity (31).

4. A dual spring hydraulic tensioner according to claim 1, wherein the plunger (20) is provided with a snap spring (16) and the inner wall of the hydraulic chamber (11) is provided with a clamping groove (15) cooperating with the snap spring (16).

5. A dual spring hydraulic tensioner according to claim 1, characterized in that the plunger spring (13) is a variable pitch compression spring.

6. The dual spring hydraulic tensioner of claim 1, wherein the pressure relief valve (22) is comprised of a bonnet (220), a base (221), a spring (222) and a steel ball (223), and an oil passage (220 a) is provided in the bonnet (220).