JPH0530444U - Seal structure between cylinder liner and cylinder block - Google Patents

Abstract

(57) [Abstract] [Purpose] It is easy to machine and assemble, and the seal ring and cylinder liner can be assembled in the cylinder block without being caught in the lateral hole that opens in the cylinder bore. [Structure] A chamfered portion 4 is formed at a ridge portion where a lower end surface 2 of a cylinder liner 1 and an outer peripheral surface 3 intersect, and a cylinder block 5 is formed.
A step portion 7 is formed in the lower portion of the cylinder bore 6, and an O-ring 8 is arranged in an annular space composed of two surfaces forming the step portion 7 and the chamfered surface 4 at the lower end of the liner. Alternatively, a ring groove is formed in the lower portion of the outer peripheral surface of the cylinder liner, and a seal ring with a lip is arranged in the ring groove so that the pressure receiving surface faces upward in the assembled state.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a cooling liquid seal structure for cooling an outer peripheral surface of a cylinder liner of an internal combustion engine.

[0002]

[Prior Art]

 FIG. 8 shows a cooling structure of a cylinder liner of a general internal combustion engine. As shown in the figure, a water jacket 51 is provided around the outer peripheral surface 3 of the cylinder liner 50. An O-ring 8 is arranged below the jacket 51 to seal the cooling water. This cylinder liner 50 can be easily inserted into the cylinder bore 54 of the cylinder block 53 without damaging the O-ring 8 after fitting the O-ring 8 in the O-ring groove 52 provided on the outer peripheral surface 3. .

Recently, attention has been paid to a groove cooling structure of a cylinder liner in which a cooling liquid groove is formed on one or both of an outer peripheral surface of a cylinder liner and an inner peripheral surface of a cylinder bore of a cylinder block, and a cooling liquid is caused to flow in the cooling liquid groove. For example, the cylinder liner disclosed in Japanese Utility Model Publication No. 3-29560 is used to change the flow rate of the cooling liquid flowing in the groove to control the cooling capacity according to the position of the cylinder liner. Is.

In this type of cooling structure, for example, when the cooling liquid is water, a horizontal hole is provided in the cylinder block to serve as an outlet or an inlet of the cooling liquid, and further, in the lower part so that the cooling liquid does not flow down to the crankcase. A seal ring needs to be placed. Similarly, even if the cooling liquid is oil, it may have such a structure.

In this case, since the chamfer cannot be largely chamfered on the side of the cylinder bore of the lateral hole which is a passage for the cooling liquid bored in the cylinder block, the cylinder liner 20 is connected to the cylinder block 23 as shown in FIG. When inserted into the cylinder bore 24, the sealing O-ring 8 is caught in the lateral hole 9 of the cylinder block 23 and damaged.

[0006]

[Problems to be solved by the device]

 In order to avoid this, the following method can be considered. (1) As shown in FIG. 4, the lower portion of the cylinder liner 30 has a smaller diameter than the portion where the lateral holes 9 and 10 provided in the cylinder block 31 are arranged, and the lower portion of the corresponding cylinder bore 32 has a smaller diameter. An O-ring groove 33 is provided on the outer peripheral surface of the small diameter portion of the lower portion of the cylinder liner 30 to arrange the O-ring 8. With this configuration, when the cylinder liner 30 is inserted into the cylinder bore 32 of the cylinder block 31, the O-ring 8 can be inserted without contacting the lateral holes 9 and 10, so that the O-ring 8 can be engaged with the lateral holes 9 and 10. It is possible to prevent penetration. (2) As shown in FIG. 5, the rod 35 is inserted into the lateral holes 9 and 10 provided in the cylinder block 23 from the outside of the cylinder block 23 to the position of the inner peripheral surface of the cylinder bore 24 to form the lateral holes 9 and 10. Block and insert the cylinder liner 20. With this configuration, the lateral holes 9 and 10 are closed by the rod 35, so that the O-ring 8 can be prevented from being caught in the lateral holes 9 and 10. (3) As shown in FIG. 6, an O-ring groove 42 is provided on the inner peripheral surface of the cylinder bore 41 of the cylinder block 40. With this configuration, when the cylinder liner 43 is inserted into the cylinder bore 41, the O-ring 8 does not pass through the lateral holes 9 and 10, so that the O-ring 8 is caught in the lateral holes 9 and 10. Can be prevented.

However, in the above (1), since the O-ring arrangement portion of the cylinder liner is thin and easily deformed, there is a problem that the seal tends to be incomplete. In the above (2), there is a problem that the lateral hole needs to penetrate straight from the outer side to the inner side of the cylinder block, and the assembly is troublesome. The above item (3) has a problem that it cannot be used when the machining of the cylinder block and the assembly of the cylinder liner are troublesome and the pitch between the cylinder bores is small and the wall thickness between the bores of the cylinder block is thin.

As described above, the above method requires extra labor at the time of assembling and is less reliable in sealing.

An object of the present invention is to provide a seal structure which is easy to process and assemble, and which allows the cylinder liner to be incorporated in the cylinder block without the seal ring being caught in the lateral hole opened in the cylinder bore. .

[0010]

[Means for Solving the Problems]

 According to the structure of the present invention, the cylinder liner is inserted into the cylinder bore of the cylinder block, and the seal structure between the cylinder liner and the cylinder block is located at a position lower than the horizontal hole for the coolant passage opening on the inner peripheral surface of the cylinder bore. , A chamfer is provided at the ridge where the lower end surface of the cylinder liner intersects with the outer peripheral surface, and a step is provided at the lower part of the cylinder bore, and an annular space consisting of two surfaces forming the step and the chamfered surface. It is characterized in that an O-ring is arranged on the.

Further, the present invention may have the following configurations. That is, a ring groove is formed on the outer peripheral surface of the cylinder liner at a position lower than the lateral hole, and a seal ring with a lip is provided in the ring groove so that the pressure receiving surface is the upper side in the assembled state. Deploy.

Here, when the seal ring is arranged in a direction in which the contact pressure with the inner peripheral surface of the cylinder bore of the lip increases when the coolant pressure increases, the surface above the lip is conveniently used as the pressure receiving surface. I shall call it.

[0013]

[Action]

 According to the first aspect, the O-ring is previously placed on the step portion on the cylinder block side, and then the cylinder liner is inserted. Therefore, since the O-ring does not pass through the lateral hole when the cylinder liner is inserted, it is possible to prevent the O-ring from being caught in the lateral hole. When the cylinder liner is fastened to the cylinder block, the O-ring is compressed between the two surfaces forming the step portion of the cylinder bore and the chamfered surface at the lower end of the cylinder liner to seal the cooling liquid.

According to the second aspect, the seal ring with a lip is fitted into the ring groove of the outer peripheral surface of the cylinder liner so that the pressure receiving surface faces upward, and then the cylinder liner is inserted into the cylinder bore of the cylinder block. At this time, the lip temporarily bulges out in the lateral hole, but when the cylinder liner is further pushed down, the lip receives pressure from the lower edge of the lateral hole and bends inward and becomes caught. Never. Then, the lip is compressed between the bottom surface of the ring groove and the inner peripheral surface of the cylinder bore to seal the cooling liquid.

[0015]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, the cylinder liner 1 has a chamfered portion 4 formed at a ridge where the lower end surface 2 and the outer peripheral surface 3 intersect. Further, a step portion 7 is provided in the cylinder bore 6 portion on the cylinder block 5 side facing the chamfered portion 4 of the cylinder liner 1. An O-ring 8 is mounted in an annular space composed of two surfaces forming the step portion 7 of the cylinder bore 6 and the chamfered surface 4 of the cylinder liner 1.

The cylinder block 5 is formed with two upper and lower lateral holes 9 and 10 for the cooling liquid passages, the upper lateral hole 9 being for the cooling liquid inlet and the lower lateral hole 10 for the cooling liquid. It is a horizontal hole for the outlet of the cooling liquid. A coolant groove is formed on the outer peripheral surface 3 of the cylinder liner 1 fitted into the cylinder bore 6 of the cylinder block 5.

The cooling liquid groove is formed by a plurality of annular grooves 11a axially spaced on the outer peripheral surface 3 of the cylinder liner 1 and a plurality of axial grooves 11b communicating the adjacent annular grooves 11a with each other. And an axial groove 11c for discharge connected to the annular groove 11a at the lower end. The plurality of axial grooves 11b are alternately arranged at positions separated by 180 degrees along the axial direction. The axial groove 11b at the lower end and the axial groove 11c for discharge are also arranged at positions separated by 180 degrees. The uppermost axial groove 11b communicates with the upper lateral hole 9, and the discharge axial groove 11c communicates with the lower lateral hole 10.

Therefore, the cooling liquid enters the axial groove 11b of the cylinder liner 1 from the lateral hole 9 on the upper side of the cylinder block 5, and sequentially flows from the top to the bottom of the cylinder liner 1 in the annular groove 11a to be discharged. It enters the lateral hole 10 on the lower side through the axial groove 11c and is returned into the cylinder block 5. In this case, since the O-ring 8 is mounted between the cylinder bore 6 of the cylinder block 5 and the cylinder liner 1, the coolant is prevented from flowing out to the lower crankcase.

Explaining the mounting of the O-ring 8 described above, the O-ring 8 is previously placed on the step portion 7 of the cylinder bore 6, and then the cylinder liner 1 is inserted into the cylinder bore 6 and the cylinder head and the cylinder block 5 are tightened to tighten the cylinder liner 1. To fix. As a result, the O-ring 8 can be compressed between the two surfaces forming the step portion 7 of the cylinder bore 6 and the chamfered surface 4 of the cylinder liner 1 to seal the cooling liquid. Since the O-ring 8 does not pass through the lateral holes 9 and 10 when inserting the cylinder liner 1, it is possible to prevent the O-ring 8 from being caught in the lateral holes 9 and 10.

FIG. 3 shows another embodiment, which is the same as the above embodiment except for the cooling liquid seal portion at the lower portion of the cylinder liner, and therefore the description thereof will be omitted. Only the cooling liquid seal portion will be described below. A ring groove 21 is formed in the outer peripheral surface 3 of the lower portion of the cylinder liner 20, and a seal ring 22 with a lip is attached to the ring groove 21 such that the pressure receiving surface faces upward. The seal ring 22 with a lip has a shape in which a bifurcated lip 22b is provided on the upper surface of a lower portion 22a having a rectangular cross section so as to project outward.

The mounting of the seal ring 22 will be described. After the seal ring 22 with a lip is fitted into the ring groove 21 of the outer peripheral surface 3 of the cylinder liner 20, the cylinder liner 20 is attached to the cylinder block 23. Insert it into the cylinder bore 24. At that time, the lip 22b temporarily protrudes from the lateral holes 9 and 10, but when the cylinder liner 20 is further pushed down, the lip 22b receives the pressure from the lower edge of the lateral holes 9 and 10 and is inward. It does not bend or get caught. Then, with the cylinder head and the cylinder block 23 tightened to fix the cylinder liner 20, the lip 22b of the seal ring 22 is compressed between the bottom surface 21a of the ring groove 21 and the inner peripheral surface of the cylinder bore 24 to seal the cooling liquid. can do.

As the cooling liquid groove formed on the outer peripheral surface of the cylinder liner, in addition to the groove having the above-described structure, for example, a spiral groove or a groove shown in Japanese Utility Model Publication No. 3-29560, that is, a plurality of annular shapes. The plurality of annular grooves are divided into a plurality of annular groove groups, and the annular grooves are made to communicate with each other. Two axial grooves that form the outlet and the inlet of the cooling liquid are formed, and the adjacent annular groove groups are connected in series with the outlet and the inlet of the cooling liquid. There are various types, such as those with a cross-sectional area that decreases from the bottom to the top in the axial direction of the liner.

In addition, as for the lateral holes that open to the cylinder bore, the upper lateral hole may be for the outlet and the lower lateral hole may be for the inlet. Only one other lateral hole is formed for the inlet or the outlet. It may not be.

[0024]

[Effect of the device]

 As described above, according to the seal structure of the present invention, the seal ring and the cylinder liner can be easily attached to the cylinder block without the seal ring being caught in the lateral hole that opens in the inner peripheral surface of the cylinder bore. The sealing structure is also simple, the processing is easy, and the sealing is reliable.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, (a) is a longitudinal sectional view showing a part of a cylinder liner inserted in a cylinder block, and (b) is an enlarged view of a main part thereof.

FIG. 2 is a front view of the cylinder liner of FIG.

3A and 3B show another embodiment of the present invention, in which FIG. 3A is a vertical cross-sectional view showing a part of a cylinder liner inserted in a cylinder block, FIG. 3B is an enlarged view of a main part thereof, and FIG. It is a principal part enlarged view which shows the state at the time of insertion.

FIG. 4 shows a comparative example, (a) is a longitudinal sectional view showing a part of a cylinder liner inserted in a cylinder block, (b).
Is an enlarged view of the main part.

FIG. 5 shows a comparative example, (a) is a longitudinal sectional view showing a part of a cylinder liner when it is inserted into a cylinder block,
(B) is an enlarged view of a main part thereof.

FIG. 6 shows a comparative example, (a) is a longitudinal sectional view showing a part of a cylinder liner inserted in a cylinder block, (b).
Is an enlarged view of the main part.

FIG. 7 is a longitudinal sectional view showing an O-ring portion when a cylinder liner is inserted into a cylinder block, showing a conventional example.

FIG. 8 is a vertical cross-sectional view showing a part of a cylinder liner inserted in a cylinder block according to a conventional example.

[Explanation of symbols]

 1, 20 Cylinder liner 2 Lower end surface 3 Outer peripheral surface 4 Chamfered portion 5, 23 Cylinder block 6, 24 Cylinder bore 7 Stepped portion 8 O-ring 9, 10 Horizontal hole 11a Annular groove 11b, 11c Axial groove 21 Ring groove 22 Lip seal Ring 22a Ring bottom 22b Lip

Claims (2)

[Scope of utility model registration request] 1. A seal structure between a cylinder liner and a cylinder block, wherein a cylinder liner is inserted into a cylinder bore of a cylinder block, and the seal structure between the cylinder liner and the cylinder block is located at a position lower than a lateral hole for a coolant passage opening on an inner peripheral surface of the cylinder bore. A chamfer is provided at the ridge where the lower end surface of the liner intersects with the outer peripheral surface, and a step is provided at the lower part of the cylinder bore, and an O-ring is provided in the annular space consisting of the two surfaces forming the step and the chamfer. A seal structure between the cylinder liner and the cylinder block, which is characterized by being arranged. 2. A seal structure between a cylinder liner and a cylinder block at a position lower than a lateral hole for a coolant passage opening in an inner peripheral surface of the cylinder bore, wherein a cylinder liner is inserted into a cylinder bore of the cylinder block. A cylinder groove characterized in that a ring groove is formed on the outer peripheral surface of the cylinder liner at a position lower than the hole, and the seal ring with a lip is arranged in the ring groove so that the pressure receiving surface faces upward in the assembled state. Seal structure between liner and cylinder block.