GB2172651A

GB2172651A - Sealing wet cylinder liners in cylinder blocks

Info

Publication number: GB2172651A
Application number: GB08507105A
Authority: GB
Inventors: Frederick Stanley Johnson
Original assignee: Rover Co Ltd
Current assignee: Rover Co Ltd
Priority date: 1985-03-19
Filing date: 1985-03-19
Publication date: 1986-09-24
Also published as: GB8507105D0

Abstract

A groove or grooves, 9a,b to 12a,b extend around the periphery of the liners and sealant is spread around each groove to seal the lower end of the jacket by being forced into an inlet communicating with the groove, whereupon it travels around the groove before emerging from an outlet. The grooves may be formed in the block and/or liners. <IMAGE>

Description

SPECIFICATION Cylinder block This invention relates to cylinder blocks of internal combustion engines.

Cylinder blocks often have wet liners, that is, liners the exterior surface of which defines a cooling jacket, to define the cylinders. To provide sealing for the cooling jacket at its lower end, that is, the end remote from the cylinder head, the block may be provided with grooves extending around the periphery of each liner, and O-rings may be inserted into the grooves in order to seal when the liner is assembled into the block. The cooling jacket may be sealed at its upper end by the cylinder head gasket.

The invention provides a cylinder block, in which the cylinders are defined by liners, the exterior surface of which defines a cooling jacket, in which a groove extends around the periphery of each liner for sealing the end of the cooling jacket that is remote from the cylinder head, and in which there is an inlet and outlet for each groove to enable the groove to be filled by injection of sealant into the inlet when the liner is in position.

The provision of the inlet and outlet for the groove enables the seal to be reliably made since the sealant is not forced out of the outlet until the entire groove is filled with sealant.

The grooves may be formed in the block, in the liners, or by both the block and the liners together.

A cylinder block of an internal combustion engine will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an axial view partly in section through the cylinder block with two liners removed; and Figure 2 is a split section, the ieft-hand side being taken through the lines A-A in Fig. 1 and the right-hand side being taken through the lines B-B in Fig. 1.

The head of the engine is not shown. The block has separate liners (two of which 1, 2 are shown) for the cylinders, which are in-line.

The block is integral with the crankcase. The inlets to the cooling jackets defined by the liners are shown by 13 and the outlets by 14.

Each liner has a circular ledge 1 a, 2a, at its upper end and the block has four corresponding circular shoulders 5 to 8 on which the ledges seat. At the lower end of the liner, the block has two circular grooves 9a to 1 2a and 9b to 1 2b for each cylinder.

Inlets 9c to 12c communicate with the grooves 9a,b to 12a,b respectively, and diametrically opposite outlets 9d to 12d also communicate with the grooves 9a,b, to 12a,b, respectively.

The assembly of the liners into the block is as follows. A sealant, such as an anaerobic sealant (such a sealant sets when air has been totally excluded), is spread around the perpheries of the ledges la, 2a etc, and the liners are inserted into the respective apertures in the block until the ledges 1 a, 2a etc firmly seat on shoulders 5 to 8 respectively. A two part acrylic sealant (one part being a curing agent) is then injected into inlet 9c. This is forced into grooves 9a and 9b and around their peripheries, whereupon it emerges from outlet 9d. Thus the operator merely has to wait for sealant to be forced out of the outlet 9d to ensure that grooves 9a,b have been filled. Sealant is injected into inlets 10c to 12c in the same way and, when it emerges from outlets 10d to 12d, filling of the grooves is ensured.Tests have established that the sealant passes equally into the two semi-circular channels between inlet and outlet and there is no risk, providing the block and liner are not contaminated, of the sealant passing down one semi-circular side of the gooves only.

In this way, the sealing of the upper and lower ends of the water jackets surrounding each cylinder is accomplished in a simple fashion. Other sealants could be used in place of acrylic sealants: for example, R.T.V. (room temperature vulcanising) rubber or silicone sealants which set at room temperature; or anaerobic sealants. Any sealant is suitable provided that: it is not degraded by exposure to oil or water/antifreeze or the temperatures encountered in use; it does not attack the metals with which it is in contact (for example steel for the liner and aluminium for the block); it remains flexible when set; and it bonds to the liner and block or simply blocks the grooves in the manner of an O-ring blocking a groove. The viscosity must not be too low or the sealant could escape from the sides of the grooves (upwards and downwards as seen in the drawings).Equally, the viscosity should not be so high that undue force was needed to inject the sealant. A low pressure, such as could be applied by hand, should be sufficient.

The block may be a one-piece casting, but equally could comprise two parts joined together on a plane containing the axes of the cylinders, as in the Applicants co-pending Application No 8428510. The invention is particularly suited to the latter case since the two parts could not be brought together around an O-ring already positioned on the liner since the O-ring would be unevenly stressed.

1. A cylinder block, in which the cylinders are defined by liners, the exterior surface of which defines a cooling jacket, in which a groove extends around the periphery of each liner for sealing the end of the cooling jacket that is remote from the cylinder head, and in which there is an inlet and outlet for each groove to enable the groove to be filled by

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cylinder block This invention relates to cylinder blocks of internal combustion engines. Cylinder blocks often have wet liners, that is, liners the exterior surface of which defines a cooling jacket, to define the cylinders. To provide sealing for the cooling jacket at its lower end, that is, the end remote from the cylinder head, the block may be provided with grooves extending around the periphery of each liner, and O-rings may be inserted into the grooves in order to seal when the liner is assembled into the block. The cooling jacket may be sealed at its upper end by the cylinder head gasket. The invention provides a cylinder block, in which the cylinders are defined by liners, the exterior surface of which defines a cooling jacket, in which a groove extends around the periphery of each liner for sealing the end of the cooling jacket that is remote from the cylinder head, and in which there is an inlet and outlet for each groove to enable the groove to be filled by injection of sealant into the inlet when the liner is in position. The provision of the inlet and outlet for the groove enables the seal to be reliably made since the sealant is not forced out of the outlet until the entire groove is filled with sealant. The grooves may be formed in the block, in the liners, or by both the block and the liners together. A cylinder block of an internal combustion engine will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an axial view partly in section through the cylinder block with two liners removed; and Figure 2 is a split section, the ieft-hand side being taken through the lines A-A in Fig. 1 and the right-hand side being taken through the lines B-B in Fig. 1. The head of the engine is not shown. The block has separate liners (two of which 1, 2 are shown) for the cylinders, which are in-line. The block is integral with the crankcase. The inlets to the cooling jackets defined by the liners are shown by 13 and the outlets by 14. Each liner has a circular ledge 1 a, 2a, at its upper end and the block has four corresponding circular shoulders 5 to 8 on which the ledges seat. At the lower end of the liner, the block has two circular grooves 9a to 1 2a and 9b to 1 2b for each cylinder. Inlets 9c to 12c communicate with the grooves 9a,b to 12a,b respectively, and diametrically opposite outlets 9d to 12d also communicate with the grooves 9a,b, to 12a,b, respectively. The assembly of the liners into the block is as follows. A sealant, such as an anaerobic sealant (such a sealant sets when air has been totally excluded), is spread around the perpheries of the ledges la, 2a etc, and the liners are inserted into the respective apertures in the block until the ledges 1 a, 2a etc firmly seat on shoulders 5 to 8 respectively. A two part acrylic sealant (one part being a curing agent) is then injected into inlet 9c. This is forced into grooves 9a and 9b and around their peripheries, whereupon it emerges from outlet 9d. Thus the operator merely has to wait for sealant to be forced out of the outlet 9d to ensure that grooves 9a,b have been filled. Sealant is injected into inlets 10c to 12c in the same way and, when it emerges from outlets 10d to 12d, filling of the grooves is ensured.Tests have established that the sealant passes equally into the two semi-circular channels between inlet and outlet and there is no risk, providing the block and liner are not contaminated, of the sealant passing down one semi-circular side of the gooves only. In this way, the sealing of the upper and lower ends of the water jackets surrounding each cylinder is accomplished in a simple fashion. Other sealants could be used in place of acrylic sealants: for example, R.T.V. (room temperature vulcanising) rubber or silicone sealants which set at room temperature; or anaerobic sealants. Any sealant is suitable provided that: it is not degraded by exposure to oil or water/antifreeze or the temperatures encountered in use; it does not attack the metals with which it is in contact (for example steel for the liner and aluminium for the block); it remains flexible when set; and it bonds to the liner and block or simply blocks the grooves in the manner of an O-ring blocking a groove. The viscosity must not be too low or the sealant could escape from the sides of the grooves (upwards and downwards as seen in the drawings).Equally, the viscosity should not be so high that undue force was needed to inject the sealant. A low pressure, such as could be applied by hand, should be sufficient. The block may be a one-piece casting, but equally could comprise two parts joined together on a plane containing the axes of the cylinders, as in the Applicants co-pending Application No 8428510. The invention is particularly suited to the latter case since the two parts could not be brought together around an O-ring already positioned on the liner since the O-ring would be unevenly stressed. CLAIMS

1. A cylinder block, in which the cylinders are defined by liners, the exterior surface of which defines a cooling jacket, in which a groove extends around the periphery of each liner for sealing the end of the cooling jacket that is remote from the cylinder head, and in which there is an inlet and outlet for each groove to enable the groove to be filled by injection of sealant into the inlet when the liner is in position.

2. A cylinder block as claimed in claim 1, in which each groove is at least partly formed in the block.

3. A cylinder block as claimed in claim 1 or claim 2, in which each groove is at least partly formed in the liner.

4. A cylinder block as claimed in any one of claims 1 to 3, in which the inlet and outlet for each groove are diametrically opposed and lie on a line normal to the plane containing the axes of adjacent cylinders.

5. A cylinder block as claimed in any one of claims 1 to 4, in which the sealant is a mixture of two or more components, one of which is a curing agent.

6. A cylinder block as claimed in any one of claims 1 to 5, in which the sealant is a room temperature vulcanising silicone sealant or an acrylic sealant.

7. A cylinder block as claimed in any one of claims 1 to 6, in which the cylinder block comprises two parts joined together on a plane containing the axes of adjacent cylin ders.

8. A cylinder block substantially as herein before describeci with reference to the accom panying drawings.

9. An internal combustion engine having a cylinder block as claimed in any one of claims 1 to 8.