Scraper knife inclined oil cylinder for bulldozer under cold environment working condition

Abstract

A scraper knife inclined oil cylinder for a bulldozer under cold environment working conditions comprises a cylinder body and a piston rod, a cylinder bottom is arranged at one end of the cylinder body, a guide sleeve is arranged at the other end of the cylinder body, the guide sleeve is provided with a connecting portion located outside the cylinder body, the connecting portion is connected with a balance valve, and one end of the balance valve is communicated with a rod cavity of the cylinder body through the guide sleeve. The other end of the balance valve is communicated with a rodless cavity of the cylinder body through an insertion type oil pipe, an insertion type connector is arranged on the cylinder bottom, the insertion type oil pipe is connected with the insertion type connector, and a plurality of cushion valve sets are arranged on a piston of the piston rod. The scraper knife inclined oil cylinder for the bulldozer under the cold environment working condition is suitable for the working condition that the temperature difference between the oil cylinder and the oil cylinder is large before and after operation, stable operation of the hydraulic oil cylinder is guaranteed, and the impact watching capacity of the oil cylinder is effectively protected through a built-in buffering structure; meanwhile, the buffering range can be changed by adjusting the length of the valve element so as to meet different buffering requirements of a main machine, and therefore ideal application under the extreme environment working condition is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of engineering machinery, in particular to a blade tilting oil cylinder for a bulldozer in cold environment working conditions. Background Art

[0002] The working environment of bulldozers is becoming more and more demanding. As the core actuator, the hydraulic cylinder has high requirements for its life and effective execution performance in extremely cold environments, which reflects the high-end stability of the machinery. At present, some special cylinders are equipped with large-cavity buffer structures, such as excavator hydraulic cylinders. However, hydraulic cylinders with buffer devices in both large and small cavities are generally more complicated, which increases the difficulty of processing and assembly, and it is difficult to achieve long-term and effective buffering effects. They occupy the space of the cylinder and have poor adaptability.

[0003] Conventional oil cylinders with large and small chambers connected to the balancing valve mostly use welded oil pipes to connect the large and small chambers to the valve seat and then to the balancing valve. In this way, under working conditions with large temperature differences, the contraction of the oil pipe will cause cracks at the welding point, resulting in oil leakage quality problems. It cannot be replaced after damage and can only be returned to the factory for repair, which seriously affects the service life of the product; the current buffer structure is to add a buffer sleeve and add a buffer groove on the guide sleeve and add a plunger to the tail of the piston rod. This structure relies on the guide sleeve groove and the buffer sleeve at the moment of combination when the limit displacement is about to be reached. High pressure is generated in the rod chamber, thereby increasing the resistance of the work and reducing the speed of the piston rod displacement, thereby achieving the purpose of buffering; but the high pressure generated instantly has high requirements on the wall thickness of the cylinder, and it is rarely used on oil cylinders with low telescopic frequency. When resetting, the buffer plunger first enters the oil port to achieve the buffering effect by reducing the resistance generated by the oil flow. The disadvantage of this structure is that it requires additional parts, which will increase the cost and increase the weight of the oil cylinder, which does not meet the development goals of high efficiency and lightweight. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a blade tilting cylinder for a bulldozer in cold environment working conditions with a simple structure and good effects.

[0005] The present invention is implemented with the following technical scheme: a blade tilting cylinder for a bulldozer working in cold environment, comprising a cylinder body and a piston rod, one end of the cylinder body is provided with a cylinder bottom, the other end of the cylinder body is provided with a guide sleeve, the guide sleeve is provided with a connecting portion located outside the cylinder body, the connecting portion is connected with a balancing valve, one end of the balancing valve is connected with a rod cavity of the cylinder body through the guide sleeve, the other end of the balancing valve is connected with a rodless cavity of the cylinder body through an inserted oil pipe, an inserted joint is provided on the cylinder bottom, the inserted oil pipe is connected to the inserted joint, and a plurality of buffer valve groups are provided on the piston of the piston rod.

[0006] The invention further comprises: the cylinder bottom is welded on the cylinder body.

[0007] One end of the plug-in joint is fixed on the cylinder bottom, and the other end of the plug-in joint is connected with the plug-in oil pipe.

[0008] Six buffer valve groups are evenly distributed on the piston.

[0009] The buffer valve group includes two one-way valves arranged opposite to each other.

[0010] The two one-way valves are arranged along the axial direction of the piston, the two one-way valves are connected to each other, and the valve stems of the one-way valves are arranged on the outside of the piston.

[0011] The buffer valve group includes two valve cores. The piston is provided with a valve slot for placing the valve cores. The two valve cores are connected together by a spring. Limit blocks for limiting the position of the valve cores are provided at both ends of the valve slot.

[0012] The valve groove passes through the piston, and the end of the valve core extends out of the piston under the action of the spring.

[0013] A sealing device is provided at the contact point between the valve core and the limit block.

[0014] The sealing device is respectively arranged on the inclined surfaces of the valve core and the limit block, and the two inclined surfaces cooperate with each other to achieve a sealing effect.

[0015] The present invention has the following advantages: the blade tilting cylinder for a bulldozer in cold environment working conditions of the present invention is suitable for working conditions with a large temperature difference before and after the cylinder operation, ensuring the stable operation of the hydraulic cylinder, and the built-in buffer structure effectively protects the impact resistance of the cylinder; at the same time, the buffer range can be changed by adjusting the length of the valve core to adapt to different buffering requirements of the main machine, thereby achieving ideal application under extreme environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the accompanying drawings described below are only some embodiments. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0017] In the attached picture: Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is an enlarged schematic diagram of the structure of A of the present invention; Figure 3 It is an enlarged schematic diagram of the structure at B of the present invention.

[0018] In the figure: 1, piston rod, 2, balance valve, 3, plug-in oil pipe, 4, plug-in joint, 5, cylinder bottom, 6, piston, 7, buffer valve group, 8, cylinder body, 9, guide sleeve, 71, valve core, 72, valve slot, 73, spring, 74, limit block.

[0019] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0021] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figures 1 to 3The blade tilting oil cylinder for bulldozers in cold working conditions shown in the figure comprises a cylinder body 8 and a piston rod 7. A cylinder bottom 5 is provided at one end of the cylinder body 8, a guide sleeve 9 is provided at the other end of the cylinder body 8, the guide sleeve 9 is provided with a connecting portion located outside the cylinder body 8, the connecting portion is connected with a balance valve 2, one end of the balance valve 2 is communicated with the rod chamber of the cylinder body 8 through the guide sleeve 9, and the other end of the balance valve 2 is communicated with the rodless chamber of the cylinder body 8 through the inserted oil pipe 3, an inserted joint 4 is provided on the cylinder bottom 5, the inserted oil pipe 3 is connected to the inserted joint 4, and a plurality of buffer valve groups 7 are provided on the piston 6 of the piston rod 7. The cylinder bottom 5 is welded to the cylinder body 8. The blade tilting oil cylinder for a bulldozer in cold environment working conditions of the present invention comprises a cylinder body and a piston rod used in conjunction with the cylinder body, wherein a cylinder bottom is welded to the bottom of the cylinder body, a guide sleeve is provided on the top of the cylinder body, and a balancing valve is also included, wherein two ends of the balancing valve are respectively connected to the cylinder bottom and the guide sleeve, and an inserted oil pipe and an inserted joint are provided at the connection between the balancing valve and the cylinder bottom, the inserted joint is fixed on the cylinder bottom, the inserted oil pipe is connected to the balancing valve group, and the inserted structure is adapted to environmental working conditions with large temperature differences, avoids stress concentration caused by thermal expansion and contraction, and improves reliability and stability; in addition, a plurality of buffer valve groups are provided on the piston of the piston rod, and when the piston rod is in motion, bidirectional buffering can be achieved to reduce the impact of back pressure on components. The structure of the present invention can realize long-life and stable operation of the oil cylinder in cold environment conditions. When the hydraulic cylinder starts to work, the temperature is as low as about -40°C. As the operation proceeds, the overall temperature of the oil cylinder rises. Due to thermal expansion and contraction, the length of the oil pipe changes. The matching mode of the plug-in oil pipe and the plug-in joint is plug-in, which can meet the length changes of the oil pipe and the joint, thereby achieving an adaptive state. At the same time, the buffer structure on the built-in piston, when the piston reaches the guide sleeve or the bottom of the cylinder, the internal leakage buffer valve group is forced to open, and the high pressure in the chamber is released, thereby reducing the impact on the components and protecting the guide sleeve and the bottom of the cylinder. The internal leakage structure protects the oil cylinder from damage caused by excessive back pressure during use.

[0024] like Figure 1 and Figure 3 In the illustrated embodiment of a bulldozer blade tilting cylinder for cold working conditions, one end of the plug-in joint 4 is fixed on the cylinder bottom 5, and the other end of the plug-in joint 4 is connected to the plug-in oil pipe 3. After the guide sleeve of the present invention is fixed, the balance valve is fixed on the guide sleeve and connected to the oil pipe, and the other end of the oil pipe is connected to the plug-in joint, and the connection adopts a rod sealing form, which can adapt to environments with large temperature differences. Finally, the plug-in joint is inserted into the cylinder bottom and fixed by a gland.

[0025] like Figure 1 to Figure 2The bulldozer blade tilting cylinder shown in the figure has six buffer valve groups 7 evenly distributed on the piston 6. The bulldozer blade tilting cylinder for cold environment working conditions of the present invention has six internal leakage buffer valve groups installed on the piston, which are installed into the cylinder barrel along with the piston rod. When the piston rod is extended, the rodless chamber contact point is opened under the action of hydraulic pressure, and the rod chamber contact ring is compressed. During the extension process, the rodless chamber and the rod chamber are not connected. When the piston rod is extended to the maximum state, the rod chamber buffer ring and the guide sleeve are mechanically contacted, causing the rod chamber and the rodless chamber to be connected, and the pressure of the rodless chamber and the rod chamber tends to be balanced, thereby achieving a buffering effect. On the contrary, when the piston rod is retracted to the bottom, the same connection effect occurs, achieving two-way buffering of the rodless chamber and the rod chamber. During the operation of the entire cylinder, if any parts of the hydraulic cylinder are damaged, the parts can be replaced to extend the service life of the hydraulic cylinder in the bulldozer environment.

[0026] like Figure 1 to Figure 2 The illustrated embodiment shows a bulldozer blade tilting cylinder for cold working conditions, wherein the buffer valve group 7 includes two oppositely arranged one-way valves. The two one-way valves are arranged along the axial direction of the piston 6, the two one-way valves are interconnected, and the valve stems of the one-way valves are arranged on the outside of the piston 6. The buffer valve group of the present invention includes two oppositely arranged one-way valves, the valve stems of the one-way valves are arranged on the outside of the piston, the two one-way valves are interconnected, and when the piston rod moves in the cylinder body, the one-way valves are triggered to open at the two ends to achieve pressure relief, thereby protecting the cylinder body components.

[0027] like Figure 1 to Figure 2 The illustrated embodiment shows a blade tilting oil cylinder for a bulldozer in cold working conditions, wherein the buffer valve group 7 includes two valve cores 71, a valve slot 72 for placing the valve core is provided on the piston 6, the two valve cores are connected together by a spring 73, and both ends of the valve slot are provided with a stop block 74 for limiting the position of the valve core. The valve slot 72 passes through the piston 6, and the end of the valve core 71 extends out of the piston 6 under the action of the spring 73. A sealing device is provided at the contact point between the valve core 71 and the stop block 74. The sealing device is respectively provided on the inclined surfaces on the valve core 71 and the stop block 74, and the two inclined surfaces cooperate with each other to achieve a sealing effect. The buffer valve group of the present invention can also be realized by two valve cores arranged in the piston. A valve groove for placing the valve core is provided in the piston. The valve groove connects the two sides of the piston. When the valve core is placed in the valve groove, a spring is arranged between the valve cores. Limit blocks are arranged at both ends of the valve groove. The valve core is sealed with the limit blocks under the action of the spring. The sealing surfaces are all inclined surfaces. During operation, when the piston rod is in the extreme position, the valve core is pushed, and the channel of the valve groove is opened, connecting the two cavities on both sides of the piston rod to achieve the effect of pressure relief.

[0028] The blade tilting cylinder for a bulldozer in cold environment conditions of the present invention is used in extremely cold environment conditions, can effectively reduce the deformation stress caused by temperature difference changes and internal pressure, and improve the adaptability of the cylinder in such environmental conditions, and realizes the bidirectional buffering effect of the hydraulic cylinder during the extreme stroke and resetting by arranging two one-way valves in the piston rod, thereby reducing the impact of back pressure on components; the external valve group, oil pipe, and joints are all detachable, and damaged components can be replaced without disassembling the cylinder; the plug-in structure can adapt to environmental conditions with large temperature differences, avoid stress concentration caused by thermal expansion and contraction, and improve reliability and stability; the present invention can implement the design of the hydraulic cylinder in an assembled form, and realize buffering under various conditions of extreme stroke of the hydraulic cylinder at a relatively low cost, while protecting the adaptability of various parts of the hydraulic cylinder in extremely cold environments, and increasing the reliability and stability of the cylinder product.

[0029] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0030] In addition, those skilled in the art will understand that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments also means being within the scope of protection of the present invention and forming different embodiments. For example, in the above embodiments, those skilled in the art can use them in combination according to the known technical solutions and the technical problems to be solved by this application.

[0031] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A blade tilt cylinder for a bulldozer in cold working conditions, characterized in that: The invention comprises a cylinder body (8) and a piston rod (7), wherein one end of the cylinder body (8) is provided with a cylinder bottom (5), and the other end of the cylinder body (8) is provided with a guide sleeve (9), and the guide sleeve (9) is provided with a connecting portion located outside the cylinder body (8), and the connecting portion is connected to a balancing valve (2), and one end of the balancing valve (2) is communicated with a rod chamber of the cylinder body (8) through the guide sleeve (9), and the other end of the balancing valve (2) is communicated with a rodless chamber of the cylinder body (8) through an inserted oil pipe (3), and an inserted joint (4) is provided on the cylinder bottom (5), and the inserted oil pipe (3) and the inserted joint (4) are connected together, and a plurality of buffer valve groups (7) are provided on the piston (6) of the piston rod (7).

2. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 1, characterized in that: The cylinder bottom (5) is welded to the cylinder body (8).

3. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 1, characterized in that: One end of the plug-in joint (4) is fixed on the cylinder bottom (5), and the other end of the plug-in joint (4) is connected to the plug-in oil pipe (3).

4. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 1, characterized in that: Six buffer valve groups (7) are evenly distributed on the piston (6).

5. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 1, characterized in that: The buffer valve group (7) comprises two one-way valves arranged opposite to each other.

6. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 5, characterized in that: The two one-way valves are arranged along the axial direction of the piston (6), the two one-way valves are connected to each other, and the valve stems of the one-way valves are arranged on the outside of the piston (6).

7. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 1, characterized in that: The buffer valve group (7) comprises two valve cores (71), the piston (6) is provided with a valve groove (72) for accommodating the valve cores, the two valve cores are connected together via a spring (73), and limit blocks (74) for limiting the position of the valve cores are provided at both ends of the valve groove.

8. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 7, characterized in that: The valve groove (72) passes through the piston (6), and the end of the valve core (71) extends out of the piston (6) under the action of the spring (73).

9. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 7, characterized in that: A sealing device is provided at the contact point between the valve core (71) and the limit block (74).

10. The blade tilt cylinder for a bulldozer in cold environment as claimed in claim 7, characterized in that: The sealing devices are respectively arranged on the inclined surfaces of the valve core (71) and the limit block (74), and the two inclined surfaces cooperate with each other to achieve a sealing effect.

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