A hydraulic tensioner for engine connecting rod assembly

Abstract

This utility model discloses a hydraulic tensioner for engine connecting rod assembly, belonging to the technical field of hydraulic tensioners. This utility model includes at least two hydraulic units arranged vertically, with a tie rod penetrating the inner cavity of each hydraulic unit. Each hydraulic unit includes a piston and a cylinder arranged inner and outer. The inner wall of the cylinder forms an inner boss, and the outer peripheral wall of the piston forms an outer boss. The inner boss, outer boss, inner wall of the cylinder, and outer wall of the piston form an oil cavity. The wall thickness H of the multiple cylinders gradually decreases from top to bottom. This utility model adopts a multi-stage tensioning structure, which can ensure tensioning force by reducing the cylinder diameter. Simultaneously, since the pressure required to withstand each stage of the cylinder gradually decreases from top to bottom, the wall thickness of the upper cylinder can be designed to be thinner, thereby further reducing the cylinder diameter to meet the needs of use in smaller spaces.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic tensioner technology, and more specifically, relates to a hydraulic tensioner for engine connecting rod assembly. Background Technology

[0002] A hydraulic bolt tensioner, also known as a hydraulic tensioner, typically consists of a hydraulic pump, a high-pressure hose, a pressure gauge, and a tensioning body. During operation, high-pressure oil from the power source is delivered via the high-pressure hose to the sealed space formed by the cylinder and piston. Under pressure, the piston in the cylinder moves upward, thus elongating the bolt threaded to the piston. When the bolt is elongated to the required deformation, it is pre-tightened or disassembled. Finally, the bolt is restored to its original shape via hydraulic or mechanical return, completing the entire process.

[0003] However, in traditional hydraulic tensioners, there is only one cylinder and one piston. When the system pressure is constant and the space around the tensioner is large enough, the required tensile force can be met. But when the space around the tensioner is limited, the cylinder diameter is also limited, causing the tensioning force to fall short of the requirements, necessitating improvement. For example, in the field of high-speed, high-power marine diesel engines, the two connecting rod bolts on one side are very close together. If a traditional hydraulic tensioner is used, the two bolts can usually be tensioned separately in two stages, which can easily lead to asymmetrical installation of the engine connecting rod, severely affecting its service life.

[0004] To this end, the applicant disclosed a dual-synchronous three-stage hydraulic tensioner in patent CN212706583U. This application includes a cylinder body and tie rods. The cylinder body comprises a first cylinder, a second cylinder, and a third cylinder connected sequentially from top to bottom. The tie rods comprise two parallel tie rods that pass sequentially through the first, second, and third cylinders, with a first piston, a second piston, and a third piston respectively positioned between the two tie rods and the three cylinders.

[0005] The aforementioned application, by incorporating two parallel tie rods within the cylinder body, with each tie rod corresponding to three cylinder blocks and pistons externally, allows for the simultaneous tensioning of two tie rod bolts on a diesel engine. This facilitates engine assembly quality, improves assembly efficiency, and extends its service life. Furthermore, the three-stage hydraulic structure effectively enhances the tensioning force and efficiency. However, with the trend towards lightweight and miniaturized diesel engine connecting rod designs, further reducing the size of the hydraulic tensioner to accommodate the simultaneous tensioning of smaller diesel engine connecting rod bolts is of significant practical importance in production. Utility Model Content

[0006] The problem to be solved To address at least some of the problems existing in the prior art, this utility model provides a hydraulic tensioner for engine connecting rod assembly. The technical solution of this utility model can effectively reduce the size of the hydraulic tensioner to accommodate the synchronous tensioning of smaller diesel engine connecting rod bolts.

[0007] Technical solution To solve the above problems, the technical solution adopted by this utility model is as follows: The present invention provides a hydraulic tensioner for assembling engine connecting rods, comprising a hydraulic cylinder assembly consisting of at least two hydraulic units arranged vertically, wherein a tie rod is provided through the inner cavity of the hydraulic cylinder assembly. The hydraulic unit includes a piston and a cylinder arranged in an inner and outer sleeve configuration; wherein, An inner boss is formed on the inner wall of the cylinder, and an outer boss is formed on the outer peripheral wall of the piston; the inner boss, the outer boss, the inner wall of the cylinder, and the outer wall of the piston form an oil cavity. The wall thickness H of the multiple cylinders from top to bottom is gradually reduced, and the wall thickness H refers to the thickness of the inner wall surrounding the oil cavity.

[0008] In some embodiments, a connecting sleeve is fitted onto the top of the pull rod, one end of which extends into the uppermost piston, and the connecting sleeve can move up and down and rotate synchronously with the pull rod.

[0009] In some embodiments, an end cap is connected to the top of the uppermost cylinder block, and an annular cavity is formed between the inner wall of the end cap and the connecting sleeve, and a return spring is provided in the annular cavity. The top of the upper piston extends into the annular cavity and contacts the return spring.

[0010] In some embodiments, the bottom of the hydraulic cylinder assembly is provided with a support sleeve, and the peripheral wall of the support sleeve is provided with a toggle groove. The bottom of the pull rod extends into the support sleeve, and the bottom of the pull rod is provided with a lower connecting part for connecting with the screw to be stretched.

[0011] In some embodiments, the top of the pull rod is provided with an upper connecting portion for connection with an external drive component.

[0012] In some embodiments, the upper connecting part is a quadrilateral, hexagonal, or dodecagonal inner hole, and the lower connecting part is an internally threaded hole.

[0013] In some embodiments, both the inner and outer bosses are provided with annular grooves, and a sealing ring is fitted inside the grooves.

[0014] In some embodiments, a hydraulic distributor is mounted on the outer peripheral wall of the hydraulic cylinder assembly, and the hydraulic distributor has a main channel extending axially therein. The main channel is connected to the oil inlet channel on the corresponding cylinder block through a branch channel, and the main channel is connected to a high-pressure connector.

[0015] In some embodiments, a counting component is also included, which comprises a housing and a counter located within the housing; wherein, The counting assembly is located above the hydraulic distributor, the drive rod of the counter extends into the main channel, and the end of the drive rod is located above the uppermost oil inlet channel.

[0016] In some embodiments, the hydraulic cylinder assembly includes three hydraulic units; the connecting sleeve and the tie rod are connected by radially arranged pins.

[0017] Beneficial effects Compared with the prior art, the beneficial effects of this utility model are as follows: (1) The hydraulic tensioner for engine connecting rod assembly of this utility model adopts a multi-stage tensioning structure. Under the condition of ensuring the same tensioning force, the cross-sectional area of ​​each stage cylinder can be made smaller than that of a single-stage hydraulic cylinder, thereby reducing the diameter of the cylinder and thus reducing the diameter of the hydraulic tensioner. At the same time, since the pressure required to withstand each stage cylinder gradually decreases from top to bottom, the wall thickness of the upper cylinder can be designed to be thinner, thereby further reducing the diameter of the cylinder to meet the needs of use in smaller spaces.

[0018] (2) A hydraulic tensioner for engine connecting rod assembly of the present invention has a connecting sleeve on the top of the connecting rod. The connecting sleeve can move up and down and rotate synchronously with the connecting rod. With this design, the connection between the connecting rod and the screw to be stretched can be achieved by the rotation of the connecting rod itself, without the need for the entire hydraulic tensioner to follow the movement. Therefore, there is no need to reserve a certain rotation space for the rotation of the hydraulic tensioner, which can further adapt to use in narrow spaces.

[0019] (3) The hydraulic tensioner for engine connecting rod assembly of this utility model has a hydraulic distributor mounted on the outer peripheral wall of the hydraulic cylinder assembly, which can record the number of times the hydraulic tensioner is used, so as to provide data support for the later maintenance time; at the same time, the drive rod of the counter extends into the main channel and relies on the oil pressure in the main channel to start the counting action, which can effectively avoid counting when the hydraulic tensioner is unloaded, so as to more realistically reflect the actual number of times the hydraulic tensioner works. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the structure of a hydraulic tensioner for engine connecting rod assembly according to the present invention; Figure 2 This is a top view of a hydraulic tensioner for engine connecting rod assembly according to the present invention; Figure 3 for Figure 2 Sectional view along the middle AA direction; Figure 4 for Figure 3 A magnified view of a portion of point B in the middle; Figure 5 for Figure 3 A magnified view of a portion of point C in the middle; Figure 6 This is a schematic diagram illustrating the assembly of a hydraulic tensioner for engine connecting rod assembly with the engine connecting rod according to this utility model.

[0021] In the picture: 100. Hydraulic cylinder assembly; 110. Piston; 111. Outer boss; 120. Cylinder body; 121. Inner boss; 122. Oil inlet channel; 130. Oil chamber; 140. Sealing ring; 200. Pull rod; 210. Upper connecting part; 220. Lower connecting part; 310. High-pressure connector; 320. Hydraulic distributor; 321. Main channel; 322. Branch channel; 400, Connecting sleeve; 500, End cap; 600, Return spring; 700, Support sleeve; 710, Actuating groove; 800, Counting component; 810, Housing; 820, Counter; 821, Drive rod. Detailed Implementation

[0022] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings.

[0023] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] The present invention will be further described below with reference to specific embodiments.

[0025] like Figure 1 , Figure 2As shown, this embodiment of a hydraulic tensioner for engine connecting rod assembly includes a hydraulic cylinder assembly 100 and a tie rod 200 passing through the hydraulic cylinder assembly 100. The hydraulic cylinder assembly 100 comprises at least two hydraulic units arranged vertically, for example, three hydraulic units, or even more, without specific limitation herein. Each hydraulic unit includes a piston 110 and a cylinder body 120 that are sealed together internally and externally.

[0026] The top of the pull rod 200 is provided with an upper connecting part 210 for connecting with an external drive component, and the bottom of the pull rod is provided with a lower connecting part 220 for connecting with the screw to be stretched.

[0027] Preferably, the upper connecting part 210 is a quadrilateral, hexagonal, or dodecagonal inner hole, and the lower connecting part 220 is an internally threaded hole.

[0028] This embodiment of a hydraulic tensioner for engine connecting rod assembly adopts a multi-stage tensioning structure. Under the condition of ensuring the same tensioning force, the cross-sectional area of ​​each stage cylinder 120 can be made smaller than that of a single-stage hydraulic cylinder, thereby reducing the diameter of the cylinder 120, which in turn reduces the diameter of the hydraulic tensioner.

[0029] like Figure 3 , Figure 4 As shown, in some embodiments, an inner boss 121 is formed on the inner wall of the cylinder 120, and an outer boss 111 is formed on the outer peripheral wall of the piston 110. The inner boss 121, the outer boss 111, the inner wall of the cylinder 120, and the outer wall of the piston 110 form an oil cavity 130.

[0030] Meanwhile, annular grooves are provided on both the inner boss 121 and the outer boss 111, and sealing rings 140 are installed in the grooves to ensure the sealing performance of the oil cavity 130.

[0031] Preferably, the wall thickness H of the plurality of cylinders 120 gradually decreases from top to bottom, and the outer boss 111 is located above the inner boss 121. It should also be noted that the wall thickness H here refers to the thickness of the inner wall surrounding the oil cavity 130.

[0032] In this embodiment, a hydraulic tensioner for engine connecting rod assembly allows for a thinner wall thickness in the upper cylinder 120 because the pressure required for each cylinder 120 gradually decreases from top to bottom. This further reduces the diameter of the cylinder 120, making it suitable for use in smaller spaces.

[0033] like Figure 1 , Figure 3As shown, in some embodiments, a connecting sleeve 400 is sleeved on the top of the pull rod 200, one end of which extends into the uppermost piston 110, and the connecting sleeve 400 can move up and down and rotate synchronously with the pull rod 200.

[0034] This design allows the connection between the tie rod 200 and the screw to be stretched to be achieved through the rotation of the tie rod itself, without the need for the entire hydraulic tensioner to follow up. Therefore, there is no need to reserve a certain amount of rotation space for the rotation of the hydraulic tensioner, which can further adapt to use in confined spaces.

[0035] Preferably, the connecting sleeve 400 and the pull rod 200 are connected by a radially arranged pin to prevent the thread from unraveling between the pull rod 200 and the connecting sleeve 400 when the pull rod 200 rotates, which is common in conventional threaded connection structures.

[0036] Furthermore, an end cap 500 is connected to the top of the uppermost cylinder 120. An annular cavity is formed between the inner wall of the end cap 500 and the connecting sleeve 400, and a return spring 600 is provided in the annular cavity.

[0037] Meanwhile, the top of the upper piston 110 extends into the annular cavity and contacts the return spring 600 to reset the stretched piston 110.

[0038] Preferably, the return spring 600 is sleeved on the outside of the connecting sleeve 400.

[0039] In other embodiments, the bottom of the hydraulic cylinder assembly 100 is provided with a support sleeve 700, and the bottom of the pull rod 200 extends into the support sleeve 700. The support sleeve 700 houses the nut to be tightened; at the same time, a shifting groove 710 is formed on the peripheral wall of the support sleeve 700. After the screw is stretched, the shifting rod can tighten the nut through the shifting groove 710.

[0040] This embodiment provides a hydraulic tensioner for assembling engine connecting rods, wherein the oil chamber 130 is equipped with an oil supply assembly.

[0041] Specifically, refer to Figure 1 , Figure 3 , Figure 4 As shown, a hydraulic distributor 320 is mounted on the outer peripheral wall of the hydraulic cylinder assembly 100. The hydraulic distributor 320 has a main channel 321 extending axially inside, and the main channel 321 is connected to a high-pressure connector 310. At the same time, the main channel 321 is connected to the oil inlet channel 122 on the corresponding cylinder body 120 through a branch channel 322.

[0042] During operation, hydraulic oil enters the main channel 321 through the high-pressure connector 310, and then enters the corresponding oil chamber 130 through the branch channels 322 and oil inlet channels 122 of each layer to lift the piston 110. The lifted piston drives the pull rod 200 to move upward through the connecting sleeve 400, which in turn drives the locking screw to be stretched.

[0043] Furthermore, hydraulic tensioners generally have a limited service life, and regular maintenance is typically performed to extend this lifespan. However, since different users may use hydraulic tensioners at varying frequencies, it's difficult to accurately determine when maintenance is needed. Therefore, in this embodiment, a counting component 800 is provided to the hydraulic cylinder assembly 100 to record the number of times the hydraulic tensioner is used in real time. The timing of maintenance can be determined based on this counting result, thereby improving its service life and safety.

[0044] It is worth mentioning that the aforementioned counting component 800 can adopt existing technology. Its specific structure and working principle can be found in patent CN223251529U, and will not be elaborated here.

[0045] In some embodiments, the counting assembly 800 includes a housing 810 and a counter 820 located within the housing 810. The counting assembly 800 is positioned entirely above the hydraulic distributor 320, and the drive rod 821 of the counter 820 extends into the main channel 321. Preferably, the end of the drive rod 821 is positioned above the uppermost oil inlet channel 122 to prevent obstruction of the inlet of that channel. Simultaneously, the drive rod 821 and the main channel 321 are sealed together using a sealing element.

[0046] Furthermore, the aforementioned housing 810 and hydraulic distributor 320 are integrally formed to ensure the sealing performance at their connection.

[0047] This embodiment of a hydraulic tensioner for engine connecting rod assembly extends the drive rod 821 into the main channel 321 and relies on the oil pressure in the main channel 321 for counting. This effectively avoids counting when the hydraulic tensioner is unloaded, thus more accurately reflecting the actual number of times the hydraulic tensioner has worked.

[0048] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A hydraulic tensioner for engine connecting rod assembly, comprising a hydraulic cylinder assembly (100) consisting of at least two hydraulic units arranged vertically, wherein a tie rod (200) is provided through the inner cavity of the hydraulic cylinder assembly (100). Its features are: The hydraulic unit includes a piston (110) and a cylinder (120) arranged in an inner and outer sleeve configuration; wherein, The inner wall of the cylinder (120) forms an inner boss (121), and the outer peripheral wall of the piston (110) forms an outer boss (111); the inner boss (121), the outer boss (111), the inner wall of the cylinder (120) and the outer wall of the piston (110) form an oil cavity (130). The wall thickness H of the multiple cylinders (120) from top to bottom is gradually reduced, and the wall thickness H refers to the thickness of the inner wall surrounding the oil cavity (130).

2. The hydraulic tensioner for engine connecting rod assembly according to claim 1, characterized in that: A connecting sleeve (400) is fitted onto the top of the pull rod (200). One end of the connecting sleeve (400) extends into the uppermost piston (110), and the connecting sleeve (400) can move up and down and rotate synchronously with the pull rod (200).

3. A hydraulic tensioner for engine connecting rod assembly according to claim 2, characterized in that: An end cap (500) is connected to the top of the uppermost cylinder (120). An annular cavity is formed between the inner wall of the end cap (500) and the connecting sleeve (400). A return spring (600) is provided in the annular cavity. The top of the upper piston (110) extends into the annular cavity and contacts the return spring (600).

4. A hydraulic tensioner for engine connecting rod assembly according to any one of claims 1-3, characterized in that: The bottom of the hydraulic cylinder assembly (100) is provided with a support sleeve (700), and the peripheral wall of the support sleeve (700) is provided with a toggle groove (710). The bottom of the pull rod (200) extends into the support sleeve (700), and the bottom of the pull rod (200) is provided with a lower connecting part (220) for connecting with the screw to be stretched.

5. A hydraulic tensioner for engine connecting rod assembly according to claim 4, characterized in that: The top of the pull rod (200) is provided with an upper connecting part (210) for connecting with an external drive component.

6. A hydraulic tensioner for engine connecting rod assembly according to claim 5, characterized in that: The upper connecting part (210) is a quadrilateral, hexagonal or dodecagonal inner hole, and the lower connecting part (220) is an internal threaded hole.

7. A hydraulic tensioner for engine connecting rod assembly according to claim 4, characterized in that: Both the inner boss (121) and the outer boss (111) are provided with annular grooves, and a sealing ring (140) is installed in the grooves.

8. The hydraulic stretcher for engine connecting rod assembly according to claim 1, characterized in that: The hydraulic cylinder assembly (100) is equipped with a hydraulic distributor (320) on its outer peripheral wall, and the hydraulic distributor (320) has a main channel (321) extending along its axial direction inside. The main channel (321) is connected to the oil inlet channel (122) on the corresponding cylinder block (120) through the branch channel (322), and the main channel (321) is connected to a high-pressure connector (310).

9. A hydraulic tensioner for engine connecting rod assembly according to claim 8, characterized in that: It also includes a counting component (800), which includes a housing (810) and a counter (820) located within the housing (810); wherein, The counting assembly (800) is located above the hydraulic distributor (320), the drive rod (821) of the counter (820) extends into the main channel (321), and the end of the drive rod (821) is located above the uppermost oil inlet channel (122).

10. The hydraulic stretcher for engine connecting rod assembly according to claim 2, characterized in that: The hydraulic cylinder assembly (100) includes three hydraulic units; the connecting sleeve (400) and the tie rod (200) are connected by a radially arranged pin.

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