Hydraulic breaking hammer with coated piston

Abstract

The application discloses a hydraulic breaking hammer with a coated piston and belongs to the breaking hammer field. The breaking hammer comprises an upper cylinder body, a middle cylinder body fixedly connected with the upper cylinder body, a lower cylinder body fixedly connected with the middle cylinder body, a piston rod inserted into the middle cylinder body, a steel drill inserted into the lower cylinder body and in transmission connection with the piston rod, a coating structure arranged on the outer wall surface of the piston rod and used for strengthening the hardness and wear resistance of the piston rod, wherein the coating structure comprises a transition layer, a strengthening layer, a surface layer and a corrosion-resistant layer; the transition layer is directly covered on the outer wall surface of the piston rod; the strengthening layer is covered on the surface of the transition layer; and the surface layer is covered on the surface of the strengthening layer. The breaking hammer sequentially covers the transition layer, the strengthening layer and the surface layer from inside to outside on the surface of the piston rod, so that the hardness of the piston rod is improved, the wall surface of the piston rod is not easy to be damaged, and the service life of the piston rod is prolonged without using conventional carburizing quenching to strengthen the piston rod and leading to the brittleness of the piston rod.

Description

Technical Field

[0001] This application relates to the field of hydraulic breaker technology, specifically a hydraulic breaker with a coated piston. Background Technology

[0002] Hydraulic breakers are typically mounted on excavators, loaders, or power stations. They offer advantages such as high impact force, ease of use, good mobility, and high efficiency, making them widely used in high-destructive operations such as mountain clearing and quarrying. Currently, existing hydraulic breakers with coated pistons generally consist of a front cylinder, a middle cylinder, and a rear cylinder. The front cylinder contains a chisel, and the middle cylinder connects to it, housing a piston that performs a fixed-cycle reciprocating motion within it. A rear oil chamber is located at the rear of the middle cylinder. To prevent oil from leaking out of the rear oil chamber through the gap between the piston and the rear of the middle cylinder, a piston sleeve is installed between the piston and the rear of the middle cylinder. Sealing rings are installed on both the inner and outer surfaces of the piston sleeve.

[0003] Conventional pistons undergo carburizing and quenching to increase their surface hardness. However, in the actual operation of a hydraulic breaker with coated pistons, the piston reciprocates within the cylinder. This reciprocating motion during impact generates friction between the piston and the cylinder. Insufficient piston surface hardness can lead to surface scoring, affecting the normal operation of the hydraulic breaker. While carburizing and quenching can typically increase piston surface hardness to 60-62 HRC, further increasing it through carburizing and quenching would result in a more brittle piston, making it prone to cracking.

[0004] Therefore, this application provides a hydraulic breaker with a coated piston to solve the above-mentioned problems. Utility Model Content

[0005] This application provides a hydraulic breaker with a coated piston, which aims to solve the problems mentioned in the background art, such as insufficient hardness of the piston in existing hydraulic breakers, which makes them prone to damage.

[0006] To achieve the above objectives, this application provides the following technical solution: a hydraulic breaker with a coated piston, comprising an upper cylinder, a middle cylinder fixedly connected to the upper cylinder, a lower cylinder fixedly connected to the middle cylinder, a piston rod inserted into the middle cylinder, a steel chisel inserted into the lower cylinder and drivenly connected to the piston rod, and a coating structure disposed on the outer wall surface of the piston rod to enhance the hardness and wear resistance of the piston rod.

[0007] The coating structure includes a transition layer, a reinforcing layer, a surface layer, and a corrosion-resistant layer. The transition layer directly covers the outer wall of the piston rod, the reinforcing layer covers the surface of the transition layer, the surface layer covers the surface of the reinforcing layer, and the corrosion-resistant layer covers the surface of the surface layer. Thus, during piston manufacturing, by sequentially covering the piston rod surface with the transition layer, reinforcing layer, and surface layer from the inside out, the hardness of the piston rod is increased without resorting to conventional carburizing and quenching to strengthen it, which could lead to piston rod embrittlement. This makes the piston rod wall less prone to scoring and extends its service life.

[0008] Preferably, in order to improve strength, the transition layer is composed of nickel, chromium, aluminum, yttrium and nano-alumina powder, and the thickness of the transition layer is 0.2-0.5μm, which improves the structural strength of the piston rod surface and thus enhances impact resistance.

[0009] Preferably, in order to improve crack resistance, the reinforcing layer is composed of a hard phase, cobalt and chromium-added nano-titanium carbide, and the thickness of the reinforcing layer is 0.2-0.5μm, which improves crack propagation resistance and thus improves the crack resistance of the piston rod.

[0010] Preferably, in order to improve wear resistance, the surface layer is made of a multilayer diamond-like film with a thickness of 0.2-0.5 μm, thereby reducing the coefficient of friction of the piston rod surface and improving wear resistance.

[0011] Preferably, the corrosion-resistant layer is a chromium base layer or a chromium nitride base layer, and the thickness of the corrosion-resistant layer is 0.2-0.5 μm.

[0012] Preferably, to improve the connection strength, the hydraulic breaker further includes an interlocking mechanism for strengthening the connection between the piston rod and the coating structure. The interlocking mechanism includes a plurality of honeycomb-shaped micropores formed on the outer wall surface of the piston rod. The plurality of honeycomb-shaped micropores are evenly distributed on the piston rod. The pore diameter of the honeycomb-shaped micropores is 0.2-0.5 μm and the depth is 1.5 μm, thereby improving the connection strength between the coating structure and the piston rod, and improving durability and stability.

[0013] This hydraulic breaker increases the hardness of the piston rod by sequentially covering the piston rod surface with a transition layer, a reinforcing layer, and a surface layer from the inside out. This avoids the piston rod becoming brittle due to conventional carburizing and quenching, thus preventing the piston rod wall from being scratched and extending the service life of the piston rod.

[0014] When the transition layer is sprayed onto this hydraulic breaker, the components of the transition layer are evenly embedded in the honeycomb micropores until they are fully distributed on the piston rod, thereby improving the connection strength between the coating structure and the piston rod, and enhancing durability and stability. Attached Figure Description

[0015] Figure 1 A schematic diagram of the structural composition of a hydraulic breaker with a coated piston;

[0016] Figure 2 for Figure 1 Enlarged diagram of point A in the middle.

[0017] In the picture:

[0018] 1. Upper cylinder block; 2. Middle cylinder block; 3. Lower cylinder block; 4. Piston rod; 5. Steel rod; 6. Coating structure; 61. Transition layer; 62. Reinforcing layer; 63. Surface layer; 64. Corrosion resistant layer; 7. Fitting mechanism; 71. Honeycomb micropores. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Example 1

[0021] This embodiment provides a hydraulic breaker with a coated piston, such as... Figure 1-2 As shown, the hydraulic breaker includes an upper cylinder 1, a middle cylinder 2 fixedly connected to the upper cylinder 1, a lower cylinder 3 fixedly connected to the middle cylinder 2, a piston rod 4 inserted into the middle cylinder 2, a steel chisel 5 inserted into the lower cylinder 3 and drivenly connected to the piston rod 4, and a coating structure 6 disposed on the outer wall of the piston rod 4 to enhance the hardness and wear resistance of the piston rod 4.

[0022] The coating structure 6 includes a transition layer 61, a reinforcing layer 62, and a surface layer 63. The transition layer 61 directly covers the outer wall of the piston rod 4, the reinforcing layer 62 covers the surface of the transition layer 61, and the surface layer 63 covers the surface of the reinforcing layer 62.

[0023] In use, by sequentially covering the piston rod 4 with a transition layer 61, a reinforcing layer 62, and a surface layer 63 from the inside out, the hardness of the piston rod 4 is increased without the piston rod 4 becoming brittle due to conventional carburizing and quenching. This makes the piston rod 4 less prone to scoring and extends its service life.

[0024] Specifically, the transition layer 61 is composed of nickel, chromium, aluminum, yttrium and nano-alumina powder, and the thickness of the transition layer 61 is 0.2-0.5 μm.

[0025] In use, nickel, chromium, aluminum, yttrium and nano alumina powder are uniformly mixed and then sprayed onto the outer wall of piston rod 4 through a supersonic flame spraying process to form a transition layer 61, which improves the structural strength of the piston rod 4 surface and thus enhances its impact resistance.

[0026] More specifically, the reinforcing layer 62 is composed of a hard phase, cobalt and chromium-added nano-titanium carbide, and the thickness of the reinforcing layer 62 is 0.2-0.5 μm.

[0027] In use, the hard phase, cobalt and chromium are uniformly mixed with nano-titanium carbide and then sprayed onto the transition layer 61 through a supersonic flame spraying process to form a reinforcing layer 62, which improves the crack propagation resistance and thus enhances the crack resistance of the piston rod 4.

[0028] Furthermore, the surface layer 63 is made of a multilayer diamond-like film, and the thickness of the surface layer 63 is 0.2-0.5 μm.

[0029] In use, the multilayer diamond-like film consists of at least three diamond-like film layers, which are deposited on the reinforcing layer 62 by magnetron sputtering to form the surface layer 63, thereby reducing the coefficient of friction on the surface of the piston rod 4 and improving wear resistance.

[0030] Furthermore, the corrosion-resistant layer 64 is a chromium base layer or a chromium nitride base layer, and the thickness of the corrosion-resistant layer 64 is 0.2-0.5μm.

[0031] In use, chromium-based and chromium nitride-based materials are sprayed onto the surface layer 63 using a supersonic flame spraying process to form a corrosion-resistant layer 64, which is suitable for highly corrosive environments, inhibits the diffusion of base metal elements into the multilayer diamond-like film layer, and improves corrosion resistance.

[0032] Example 2

[0033] Unlike Embodiment 1, an overly smooth piston rod 4 surface is not conducive to the adhesion of the coating structure 6. Therefore, the hydraulic breaker also includes a fitting mechanism 7 for strengthening the connection between the piston rod 4 and the coating structure 6. The fitting mechanism 7 includes a plurality of honeycomb-shaped micropores 71 opened on the outer wall surface of the piston rod 4. The plurality of honeycomb-shaped micropores 71 are evenly distributed on the piston rod 4. The pore diameter of the honeycomb-shaped micropores 71 is 0.2-0.5μm and the depth is 1.5μm.

[0034] When the transition layer 61 is applied, its components are evenly embedded in the honeycomb micropores 71 until they are fully distributed on the piston rod 4, thereby improving the connection strength between the coating structure 6 and the piston rod 4 and enhancing durability and stability.

[0035] It should be noted that each coating structure involved in this application has a single layer thickness of 0.2-0.5μm and a total thickness of 1-2μm, and it is necessary to ensure that the interlayer is dense and free of pores.

[0036] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be included within the scope of protection of this application.

Claims

1. A hydraulic breaker with a coated piston, comprising an upper cylinder (1), a middle cylinder (2) fixedly connected to the upper cylinder (1), a lower cylinder (3) fixedly connected to the middle cylinder (2), a piston rod (4) inserted into the middle cylinder (2), a steel rod (5) inserted into the lower cylinder (3) and drivenly connected to the piston rod (4), and a coating structure (6) disposed on the outer wall surface of the piston rod (4) for enhancing the hardness and wear resistance of the piston rod (4), characterized in that: The coating structure (6) includes a transition layer (61), a reinforcing layer (62), a surface layer (63), and a corrosion-resistant layer (64). The transition layer (61) directly covers the outer wall of the piston rod (4). The reinforcing layer (62) covers the surface of the transition layer (61). The surface layer (63) covers the surface of the reinforcing layer (62). The corrosion-resistant layer (64) covers the surface of the surface layer (63).

2. The hydraulic breaker with a coated piston according to claim 1, characterized in that: The material of the surface layer (63) is a multilayer diamond-like film, and the thickness of the surface layer (63) is 0.2-0.5μm.

3. A hydraulic breaker with a coated piston according to claim 1, characterized in that: The corrosion-resistant layer (64) is a chromium base layer or a chromium nitride base layer, and the thickness of the corrosion-resistant layer (64) is 0.2-0.5 μm.

4. A hydraulic breaker with a coated piston according to claim 1, characterized in that: The hydraulic breaker also includes a fitting mechanism (7) for strengthening the connection between the piston rod (4) and the coating structure (6). The fitting mechanism (7) includes a plurality of honeycomb micropores (71) formed on the outer wall surface of the piston rod (4). The plurality of honeycomb micropores (71) are evenly distributed on the piston rod (4). The diameter of the honeycomb micropores (71) is 0.2-0.5 μm and the depth is 1.5 μm.

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