Lock bolt device for diesel engine exhaust pipe

Abstract

The utility model discloses a lock bolt device for an exhaust pipe of a diesel engine, which comprises two exhaust pipe bolts used for fixing the exhaust pipe on a cylinder cover, the exhaust pipe is provided with exhaust pipe mounting holes through which the exhaust pipe bolts can pass, and the cylinder cover is provided with threaded mounting holes matched with the exhaust pipe bolts; a special cushion column with a certain length is arranged between a nut of the exhaust pipe bolt and the exhaust pipe in a sleeved mode, and heat dissipation holes are formed in the side wall of the special cushion column. From the perspective of reducing the temperature, the length of the exhaust pipe bolts is increased through the ingenious structural design, the tightening force is increased, meanwhile, a stretching area is located outside, and the exhaust pipe bolts are not prone to being pulled out, so that the temperature of the exhaust pipe bolts is reduced, and the service life of the exhaust pipe bolts is prolonged. And the temperature of the exhaust pipe bolt is reduced in a heat dissipation mode through the heat dissipation holes, so that the material property change caused by high temperature is avoided, meanwhile, the influence of thermal stress on bolt fastening is reduced, and the purpose of bolt looseness prevention is achieved.

Description

Technical Field

[0001] The utility model relates to an anti-loosening bolt device, which is applied to fix the exhaust pipe of a diesel engine in a high-temperature environment. Background Art

[0002] Diesel engine exhaust pipe bolts, as an important part of diesel engine exhaust pipe, fasten diesel engine exhaust pipe and cylinder head together. High temperature combustion gas is discharged through cylinder head airway and enters exhaust pipe. If exhaust pipe bolts are loose, the exhaust pipe and cylinder head cannot be sealed. High temperature gas discharge from this place will cause damage to nearby wiring harness, pipeline and other equipment, and even cause fire. Therefore, exhaust pipe bolts are special high temperature resistant bolts to meet the high temperature use environment of bolts caused by heat conduction.

[0003] However, due to the alternating effects of mechanical stress caused by vibration, exhaust capacity, thermal stress caused by temperature, and material creep at high temperature, exhaust pipe bolts will become loose after a period of use. The fundamental reason for the loosening is the tightening force generated by the original bolt stretching. Due to material changes or stress, the bolts rotate or the tensile force decreases, causing the bolts to loosen.

[0004] The existing measures to prevent the bolts from loosening are to use special anti-loosening threads and anti-loosening washers, or to use steel wire tying to add a locking layer on the nut.

[0005] However, the existing anti-loosening design through special thread structure and gasket structure, as well as the method of adding binding wire to the bolt nut, are structural improvements based on the existing length and material, and are intended to prevent the bolt from rotating through structural design, thereby achieving the anti-loosening effect. The above anti-loosening method is more effective in a static environment at room temperature. For the high temperature environment where the exhaust pipe bolt is used, the material properties of the bolt itself change due to the high temperature. Even if there is no rotation, the bolt tightening force will decrease, and the anti-loosening effect cannot be fundamentally achieved. Utility Model Content

[0006] In order to solve the above technical problems, the utility model provides an anti-loosening bolt device for a diesel engine exhaust pipe. From the perspective of lowering the temperature, firstly, the length of the bolt is increased, the stretching area of ​​the bolt is lengthened, and the stress of the bolt is reduced; secondly, a special cushion column with a heat dissipation hole is added in the stretching area, which can effectively reduce the temperature of the bolt stretching area, thereby avoiding the change of material properties caused by high temperature and preventing loosening caused by high temperature; thirdly, on this basis, a binding wire is added to prevent loosening caused by mechanical vibration; the utility model can fundamentally achieve the effect of preventing the exhaust pipe bolts from loosening.

[0007] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0008] A bolt device for preventing the exhaust pipe of a diesel engine from loosening, comprising two exhaust pipe bolts for fixing the exhaust pipe to a cylinder head, an exhaust pipe mounting hole through which the exhaust pipe bolts can pass is arranged on the exhaust pipe, and a threaded mounting hole matching the exhaust pipe bolts is arranged on the cylinder head;

[0009] A special pad column with a certain length is sleeved between the nut of the exhaust pipe bolt and the exhaust pipe, and a heat dissipation hole is opened on the side wall of the special pad column; iron wires are tied to the nuts of the two exhaust pipe bolts to prevent the exhaust pipe bolts from rotating.

[0010] A further improvement of the technical solution of the utility model is that: the heat dissipation holes provided on the special pad column are in four rows, wherein two opposite rows have two heat dissipation holes in each row, and the other two rows have one heat dissipation hole in each row.

[0011] A further improvement of the technical solution of the utility model is that the diameter of the heat dissipation hole is 3 mm.

[0012] A further improvement of the technical solution of the utility model is that the length of the special cushion column is 40 mm and the thickness is 5-6 mm.

[0013] A further improvement of the technical solution of the utility model is that the central hole of the special pad column and the screw rod of the exhaust pipe bolt are interference fit.

[0014] A further improvement of the technical solution of the utility model is that the iron wires on the nuts of the two exhaust pipe bolts are tied into an "8" shape, and second through holes through which the iron wires can pass are evenly distributed on the nuts.

[0015] A further improvement of the technical solution of the utility model is that a sealing gasket is arranged between the exhaust pipe and the cylinder head.

[0016] A further improvement of the technical solution of the utility model is that a first through hole through which the exhaust pipe bolt can pass is provided at a position on the sealing gasket corresponding to the threaded mounting hole.

[0017] Due to the adoption of the above technical solution, the technical progress achieved by the utility model is:

[0018] The utility model starts from the perspective of lowering the temperature: first, the length of the bolt is increased, the stretching area of ​​the bolt is lengthened, and the stress of the bolt is reduced; second, a special cushion column with a heat dissipation hole is added in the stretching area, and the stretching area of ​​the bolt is moved to the outside, which can effectively reduce the temperature of the bolt stretching area, thereby avoiding changes in material properties caused by high temperature and preventing loosening caused by high temperature; third, on this basis, binding wire is added to prevent loosening caused by mechanical vibration; the utility model increases the length of the exhaust pipe bolt and increases the tightening force through a clever structural design, while placing the stretching area outside, and reduces the temperature of the exhaust pipe bolt by heat dissipation through the heat dissipation hole, thereby avoiding changes in material properties caused by high temperature, and at the same time reduces the influence of thermal stress on bolt tightening, achieving the purpose of preventing bolt loosening. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model when it is installed;

[0020] Figure 2 It is a structural schematic diagram of the special cushion column of the utility model;

[0021] Figure 3 It is a cutaway schematic diagram of the special cushion column of the utility model;

[0022] Among them, 1. sealing gasket, 101. first through hole, 2. special gasket column, 201. heat dissipation hole, 3. exhaust pipe bolt, 301. second through hole, 4. iron wire, 5. exhaust pipe, 501. exhaust pipe mounting hole, 6. cylinder head, 601. threaded mounting hole. DETAILED DESCRIPTION

[0023] The existing diesel engine exhaust pipe bolt anti-loosening device is used at room temperature. After being transferred to the high-temperature exhaust pipe of the utility model, the bolts will become loose due to the combined effect of high temperature stress and mechanical stress, and the loosening problem cannot be fundamentally solved.

[0024] The utility model aims at the fundamental cause of the loosening of the exhaust pipe bolts of the diesel engine. By raising and shifting the stretching position of the bolts, high-temperature stress is prevented from being generated at the stretching position of the bolts, thereby effectively putting an end to the loosening caused by high temperature. Binding wires are added to prevent loosening caused by mechanical vibration. The utility model solves the problem of high-temperature loosening by adding special pads without changing the cylinder head and the exhaust pipe.

[0025] The present invention is further described in detail below in conjunction with the embodiments:

[0026] like Figure 1As shown, a bolt device for preventing the exhaust pipe of a diesel engine from loosening includes an exhaust pipe bolt 3 for fixing the exhaust pipe 5 to the cylinder head 6. The exhaust pipe bolts 3 are two in number and are fixed at two diagonal positions respectively. The exhaust pipe 5 is provided with an exhaust pipe mounting hole 501 through which the exhaust pipe bolts 3 can pass, and the cylinder head 6 is provided with a threaded mounting hole 601 matching the exhaust pipe bolt 3. A sealing gasket 1 is provided between the exhaust pipe 5 and the cylinder head 6, and a first through hole 101 through which the exhaust pipe bolt 3 can pass is provided at a position corresponding to the threaded mounting hole 601 on the sealing gasket 1.

[0027] A special gasket column 2 is sleeved between the nut of the exhaust pipe bolt 3 and the exhaust pipe 5. The structure of the special gasket column 2 is as follows: Figure 2 and 3 As shown, a central hole is provided in the center through which the screw of the exhaust pipe bolt 3 can pass, and the central hole and the screw are interference fit; the special pad column 2 has a certain length, preferably 40mm, which can increase the length of the screw while placing the stretching area of ​​the exhaust pipe bolt 3 outside, thereby reducing the temperature of the exhaust pipe bolt. At the same time, a heat dissipation hole 201 is provided on the side wall of the special pad column 2, and the heat dissipation through the heat dissipation hole can further reduce the temperature of the exhaust pipe bolt, thereby avoiding changes in material properties caused by high temperature. The heat dissipation holes 201 provided on the special pad column 2 are in four rows, of which two opposite rows have two heat dissipation holes 201 in each row, and the other two rows have one heat dissipation hole 201 in each row, and the diameter of the heat dissipation hole 201 is 3mm. The thickness of the special pad column 2 is generally 5-6mm.

[0028] In order to prevent the exhaust pipe bolts 3 from rotating, the nuts of the two exhaust pipe bolts 3 are both tied with iron wires 4 in the shape of "8", and the nuts are evenly distributed with second through holes 301 through which the iron wires 4 can pass, so as to facilitate the tying of the iron wires 4.

[0029] Working principle:

[0030] The utility model lengthens the exhaust pipe bolt 3, that is, the contact between the original nut and the exhaust pipe is changed to a special gasket column that contacts the nut and the exhaust pipe respectively, so as to prevent thermal stress and material creep caused by the overall high temperature of the exhaust pipe bolt 3; and there are heat dissipation holes 201 on the special gasket column 2, which effectively reduce the temperature of the exhaust pipe bolt 3, and the elongated area of ​​the bolt is basically located near the special gasket column 2, the temperature of the stretching area is not high, and the thermal stress generated is also small, which can prevent the bolt from loosening; at the same time, in order to prevent the exhaust pipe bolt 3 from rotating and loosening due to mechanical vibration and stress, a binding wire is added to prevent the bolt from loosening.

Claims

1. A bolt device for preventing the exhaust pipe of a diesel engine from loosening, comprising two exhaust pipe bolts (3) for fixing the exhaust pipe (5) to a cylinder head (6), wherein the exhaust pipe (5) is provided with an exhaust pipe mounting hole (501) through which the exhaust pipe bolts (3) can pass, and the cylinder head (6) is provided with a threaded mounting hole (601) matched with the exhaust pipe bolts (3); Features: A special gasket column (2) of a certain length is sleeved between the nut of the exhaust pipe bolt (3) and the exhaust pipe (5), and a heat dissipation hole (201) is opened on the side wall of the special gasket column (2); and iron wires (4) are tied to the nuts of the two exhaust pipe bolts (3) to prevent the exhaust pipe bolts (3) from rotating.

2. A diesel engine exhaust pipe anti-loosening bolt device according to claim 1, Features: The heat dissipation holes (201) provided on the special pad column (2) are arranged in four rows, of which two opposite rows each have two heat dissipation holes (201), and the other two rows each have one heat dissipation hole (201).

3. A diesel engine exhaust pipe anti-loosening bolt device according to claim 2, Features: The diameter of the heat dissipation hole (201) is 3 mm.

4. A diesel engine exhaust pipe anti-loosening bolt device according to claim 2, Features: The special cushion column (2) has a length of 40 mm and a thickness of 5-6 mm.

5. The anti-loosening bolt device for a diesel engine exhaust pipe according to claim 1, Features: The center hole of the special pad column (2) and the screw rod of the exhaust pipe bolt (3) are in interference fit.

6. The anti-loosening bolt device for a diesel engine exhaust pipe according to claim 1, Features: The iron wires (4) on the nuts of the two exhaust pipe bolts (3) are tied into an "8" shape, and the nuts are evenly distributed with second through holes (301) through which the iron wires (4) can pass.

7. The anti-loosening bolt device for a diesel engine exhaust pipe according to claim 1, Features: A sealing gasket (1) is provided between the exhaust pipe (5) and the cylinder head (6).

8. A diesel engine exhaust pipe anti-loosening bolt device according to claim 7, Features: A first through hole (101) through which the exhaust pipe bolt (3) can pass is provided at a position on the sealing gasket (1) corresponding to the threaded mounting hole (601).

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