External thread ratchet tensioner

Abstract

The utility model discloses an external thread ratchet tensioner which comprises a shell, a piston is arranged in the shell, a thread section is arranged outside the shell, a through hole is formed in the side, close to the end of the piston, of the thread section, and a first limiting groove corresponding to the through hole is formed in the inner wall of the shell. The width of the first limiting groove is larger than the diameter of the through hole, a ratchet groove section is arranged on the surface of the piston and comprises a plurality of ratchet grooves, one ratchet groove is sleeved with a spring clamping ring, the spring clamping ring is located in the first limiting groove, and a containing groove is formed in the side, away from the end of the piston, of the ratchet groove section. And the groove depth of the placing groove is greater than that of the ratchet groove.

Description

Technical Field

[0001] The utility model belongs to the technical field of automobile parts, and more specifically relates to an external-thread ratchet tensioner. Background Art

[0002] In the timing system of a vehicle engine, a tensioner is required to tension the slack side of the timing chain. The tensioner includes a housing and a piston. A hydraulic chamber for the axial movement of the piston is provided at the center of the housing. In order to prevent the problem of tooth skipping and noise caused by excessive backward swing of the piston, a ratchet mechanism needs to be added between the housing and the piston to realize the limiting function of the backward swing.

[0003] For example, the existing patent with the publication number CN206723376U discloses a variable pitch ratchet tensioner. A limiting groove is provided at the end of the housing, and a snap ring is located in the limiting groove. The telescopic movement of the piston can make the snap ring jump in the ratchet groove of the piston in turn.

[0004] It moves the snap ring in the limiting groove at the end of the piston. Due to the repeated telescopic movement of the piston, the snap ring may become loose. The loose snap ring loses the limiting function for the piston, and the snap ring needs to be replaced. In addition, when the piston is pushed out by a certain excessive oil pressure, the snap ring will be far away from the end of the piston, resulting in excessive extension of the piston. At this time, the position of the snap ring needs to be adjusted. However, since the snap ring is located at the end of the piston, it is difficult to take out and adjust the snap ring. Content of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the utility model provides an external-thread ratchet tensioner, which is convenient for taking out and adjusting the snap ring in the tensioner.

[0006] To achieve the above object, the utility model provides the following technical solution: an external-thread ratchet tensioner, including a housing, a piston is arranged inside the housing, a threaded section is arranged outside the housing, a through hole is arranged on one side of the threaded section close to the end of the piston, a first limiting groove corresponding to the through hole is arranged on the inner wall of the housing, the width of the first limiting groove is greater than the diameter of the through hole, a ratchet groove section is arranged on the surface of the piston, the ratchet groove section includes a plurality of ratchet grooves, a snap ring is sleeved on one of the ratchet grooves, the snap ring is located in the first limiting groove, a placement groove is arranged on one side of the ratchet groove section far away from the end of the piston, and the depth of the placement groove is greater than the depth of the ratchet groove.

[0007] Further, symmetric through holes are arranged on the housing.

[0008] Further, an opening is arranged on the snap ring, and the end face at the opening of the snap ring is an inclined surface.

[0009] Further, a second limiting groove is arranged at the end of the housing, and the diameter of the second limiting groove is smaller than that of the first limiting groove.

[0010] Further, a gap is provided between the outer wall of the piston and the inner wall of the housing.

[0011] Compared with the prior art, the beneficial effects of the present utility model are as follows: The spring snap ring is movable within the first limiting groove. When the piston extends excessively, the spring snap ring within the first limiting groove can be adjusted through the through hole on the housing, facilitating the adjustment of the spring snap ring. If it is necessary to remove the spring snap ring, the spring snap ring is adjusted into the placement groove at the end of the piston, and then the entire piston can be withdrawn from the housing, facilitating the removal of the spring snap ring. The external thread on the housing can directly mount the tensioner on the engine housing, facilitating the disassembly and assembly of the tensioner. Description of the Drawings

[0012] Figure 1 is a three-dimensional structural schematic diagram of the external thread ratchet tensioner of the present utility model;

[0013] Figure 2 is a sectional structural schematic diagram of the end part of the external thread ratchet tensioner of the present utility model;

[0014] Figure 3 is a sectional structural schematic diagram of the middle part of the external thread ratchet tensioner of the present utility model;

[0015] Figure 4 is a structural schematic diagram of the piston in the external thread ratchet tensioner of the present utility model;

[0016] Figure 5 is a structural schematic diagram of the spring snap ring in the external thread ratchet tensioner of the present utility model.

[0017] Reference numerals: housing 1; piston 2; threaded section 3; through hole 4; first limiting groove 5; ratchet groove section 6; spring snap ring 7; opening 8; second limiting groove 9; placement groove 10. Detailed Embodiments

[0018] In the description of the present utility model, it should be noted that for orientation terms, such as the terms "center", "transverse (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the orientation and position relationships indicated are based on the orientation or position relationships shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of the present utility model.

[0019] In addition, terms such as "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more such features. In the description of the present utility model, the meanings of "several" and "a number of" are two or more, unless otherwise specifically defined.

[0020] Refer to Figures 1 to 5 for further description of the present utility model.

[0021] An external thread ratchet tensioner includes a housing 1. A piston 2 is arranged inside the housing 1. A threaded section 3 is arranged outside the housing 1. A through hole 4 is arranged on one side of the threaded section 3 close to the end of the piston 2. A first limiting groove 5 corresponding to the through hole 4 is arranged on the inner wall of the housing 1. The width of the first limiting groove 5 is greater than the diameter of the through hole 4. A ratchet groove section 6 is arranged on the surface of the piston 2. The ratchet groove section 6 includes a number of ratchet grooves. A snap ring 7 is sleeved on one of the ratchet grooves. The snap ring 7 is located in the first limiting groove 5. A placement groove 10 is arranged on one side of the ratchet groove section 6 away from the end of the piston 2. The depth of the placement groove 10 is greater than the depth of the ratchet groove.

[0022] Preferably in this embodiment, the housing 1 can be directly threadedly connected to the engine housing through the threaded section 3, facilitating the disassembly and assembly of the tensioner.

[0023] As Figure 3 shown, preferably in this embodiment, symmetric through holes 4 are arranged on the housing 1.

[0024] As Figure 5 shown, preferably in this embodiment, an opening 8 is arranged on the snap ring 7, and the end face at the opening 8 of the snap ring 7 is an inclined surface.

[0025] As Figure 2 and Figure 3 shown, preferably in this embodiment, a second limiting groove 9 is arranged at the end of the housing 1. The diameter of the second limiting groove 9 is smaller than that of the first limiting groove 5. After the piston 2 is installed into the housing 1, the spring between the housing 1 and the piston 2 is compressed by a small amount, and the piston 2 is prevented from being pushed out of the housing 1 through the second limiting groove 9.

[0026] Preferably in this embodiment, a gap is arranged between the outer wall of the piston 2 and the inner wall of the housing 1.

[0027] As Figures 1 to 5As shown, after the snap ring 7 is sleeved on the piston 2, the piston 2 is installed into the housing 1. The snap ring will first be in the second limiting groove 9, and then the piston 2 is pushed out by oil pressure, so that the snap ring 7 quickly moves on the ratchet groove section 6 of the piston 2, and then the piston 2 is pushed in again, so that the snap ring 7 enters the first limiting groove 5. At this time, the snap ring 7 moves within the first limiting groove 5. When the piston 2 extends excessively, the snap ring 7 within the first limiting groove 5 can be adjusted through the through hole 4 on the housing 1, which facilitates the adjustment of the snap ring 7. If the snap ring 7 needs to be taken out, the snap ring 7 is adjusted to the placement groove 10 at the end of the piston 2, and then the entire piston 2 can be pulled out from the housing 1, which facilitates the removal of the snap ring 7.

[0028] Preferably in this embodiment, to adjust the snap ring 7, tools such as a pair of needle-nose pliers, tweezers, or a flipper that can extend into the through hole 4 can be used to clamp or move the snap ring 7 on the piston 2.

[0029] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. An externally threaded ratchet tensioner, characterized in that: It includes a shell, a piston is arranged in the shell, a threaded section is arranged on the outside of the shell, a through hole is arranged on the side of the threaded section close to the end of the piston, a first limiting groove corresponding to the through hole is arranged on the inner wall of the shell, the width of the first limiting groove is greater than the diameter of the through hole, a ratchet groove section is arranged on the surface of the piston, the ratchet groove section includes a plurality of ratchet grooves, a spring retaining ring is sleeved on one of the ratchet grooves, the spring retaining ring is located in the first limiting groove, and a placement groove is arranged on the side of the ratchet groove section away from the end of the piston, the groove depth of the placement groove is greater than the groove depth of the ratchet groove.

2. The externally threaded ratchet tensioner according to claim 1, characterized in that: The shell is provided with symmetrical through holes.

3. The externally threaded ratchet tensioner according to claim 1, characterized in that: The spring clamp is provided with an opening, and the end surface of the spring clamp opening is an inclined surface.

4. The externally threaded ratchet tensioner according to claim 1, characterized in that: A second limiting groove is arranged at the end of the shell, and the diameter of the second limiting groove is smaller than that of the first limiting groove.

5. The externally threaded ratchet tensioner according to claim 1, characterized in that: A gap is arranged between the outer wall of the piston and the inner wall of the housing.

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