SK602021A3 - Method of repairing the cylinder head of a piston machine with rectilinear reciprocating movement - Google Patents

Abstract

The method of repairing the cylinder head of a reciprocating machine with rectilinear reciprocating movement consists in milling the damaged surface (2) of the cylinder head (1) of the piston machine over the entire surface of the compression space (8) up to the level of the cooling part. Subsequently, an insert (4) replacing the originally milled surface (2) of the cylinder head (1) is designed and custom-made and fitted. For better fitting of the insert (4) and transmission of the force caused by compression, a fitting hole is milled, i. j. on two different diameters (3). The compression space (8) is sealed by the original seal (5) under the cylinder head (1), which rests on the insert (4) along the entire circumference of the compression space (8). The intake and exhaust ducts are sealed to the insert (4) by means of a sealing mastic (6) in the grooves into which the non-milled parts of these ducts abut. The original valve seats (7) and other openings / channels (eg spark plugs, injection nozzles) entering the compression chamber (8) are located directly in the insert (4), being fitted into the insert (4) in the same way as before. fitted to the cylinder head (1). A solder or O-ring can be used as an alternative seal for the insert (4). A hollow bolt (9) is used to seal the transition channel through the insert (4), which is sealed to the conical surface and screwed into the corresponding channel in the cylinder head (1).

Description

SK 60-2021 A3

Field of technology

The invention relates to a method of repairing a damaged part of the cylinder head of a piston machine without the need to replace the entire cylinder head. The invention falls into the field of mechanical engineering.

Prior art

At present, due to damage to the cylinder head of the reciprocating machine and their subsequent repairs, it is in most cases necessary to replace the entire cylinder head. Wear on the cylinder head of reciprocating machines can result in a leak in the cylinder head itself, usually due to a crack. In the event of such damage to the cylinder head of a reciprocating machine, various methods of repair are currently used, in particular repairing the cylinder head with screws, welding cracks, milling the valve seat and subsequently pressing a new valve seat with possible subsequent soldering. These cylinder head repair methods are in most cases unsuccessful and require replacement of the entire cylinder head. The object of the invention is a technological process which consists in replacing the entire active area of the cylinder head compression space with an insert of suitable material and a method of sealing it both on the coolant side and on sealing the compression chamber of various types and other machine parts entering the compression chamber through the cylinder head.

The essence of the invention

Said deficiencies in the repair of the cylinder head of the piston machine are substantially eliminated by the method of repairing a damaged part of the cylinder head according to the invention, which consists in repairing the damaged cylinder head by milling the entire effective area of the cylinder head affected overhang to the level of the space leading to the refrigerant and subsequent replacement by a custom-made liner with an overhang of the active area, sealing the compression chamber by the pressure of the original connecting material and a standard seal for the given machine. The design also ensures the sealing of the intake and exhaust ducts from the cooling medium by using a polymer-based sealant, O-ring seal or soldering.

This method of repairing the cylinder head of piston machines represents an economically and ecologically more advantageous alternative to replacing the entire cylinder head in case of problematic availability of original spare parts as well as high consumption of raw materials and energy in the case of marine engines or railway vehicles.

Overview of figures in the drawings

The method of repairing the cylinder head of a reciprocating reciprocating machine is shown in the drawings, where:

fig. 1 shows the milling of a damaged active part of the cylinder head, FIG. 2 shows a refurbished cylinder head by means of an insert fitted to a block of a piston machine, FIG. 3 shows the principle of sealing a compression-stressed channel with a hollow bolt.

Example of an embodiment of the invention

Example 1

In this example of a specific embodiment of the invention, a method of repairing the cylinder head of a reciprocating reciprocating machine is described, as shown in FIG. 1 to 3.

The procedure for repairing a damaged cylinder head of a Zetor 25 tractor is such that:

- A crack location is identified on the active surface 2 of the cylinder head 1, which closes the compression space 8.

- The entire active circular area 2 of the cylinder head 1 is milled. The diameter of the milled surface 2 must exceed the diameter of the seal hole 5 under the cylinder head 1. The circular hole is milled with a shoulder, i.e. on two different diameters 3, in order to better fit the insert 4 and to transmit compressive forces.

- The entire thickness of the material is milled to the space where the coolant was originally located.

- After removing the material by milling, a cavity is created, which must be replaced by a new insert 4. The 3D scanner as a supporting method of reverse engineering determines the exact dimensions of the milled cavity in the cylinder head 1. Based on this data, a model of insert 4 with the necessary tolerances and allowances is created in the CAD system.

SK 60-2021 A3

- The insert 4 is made of a material which is most similar in its properties to the original material of the cylinder head 1, resp. exceeds these characteristics. In this case, globular graphite cast iron is used as a suitable material.

- To create a seal between the water coolant of the cylinder head 1 and the intake resp. of the exhaust duct, grooves are milled into the insert 4, into which a suitable sealing material 6 - putty will be applied before the final fitting of the insert 4.

- For a given type of internal combustion engine, a pressure seal of the vortex chamber through the insert 4 is required. A hollow bolt 9 made of a suitable material is used, which is sealed to a conical surface and screwed directly into the respective channel in the cylinder head 1. The material of the bolt 9 is selected on the basis of the thermal, chemical and mechanical stresses which are placed on the bolt 9 when the motor is running. Aluminum bronze is used as a suitable material for this purpose.

- The hollow bolt 9 is made with an allowance, behind which it will be tightened to the appropriate moment with the help of a wrench during the final fitting of the insert 4 to the head. The insert 4 itself is also made with a machining allowance. Both of these allowances will be removed when leveling the entire head 1 by milling and, if necessary, grinding.

Industrial applicability

The method of repairing the cylinder head of a reciprocating reciprocating machine is useful for repairing damaged engines of agricultural machinery, railway vehicles, ships, stationary engines, compressors and pumps, including the mining industry and historical technical equipment.

SK 60-2021 A3

List of cylinder head reference marks damaged cylinder head working area

3 two different hole diameters for fitting insert liner original sealant sealing valves

8 compression space hollow bolt

Claims (5)

SK 60-2021 A3 PATENT CLAIMS A method of repairing a cylinder head of a reciprocating reciprocating machine, characterized in that on a piston machine with a damaged cylinder head (1) a cylinder head (1) defining the compression space (8) is performed over the entire working surface (2) of the cylinder head. , milling the damaged surface (2) of the cylinder head (1); subsequently, an insert (4) corresponding to the milled surface (2) of the cylinder head (1) is made to measure and fitted; the compression chamber (8) is sealed by the original gasket (5) under the cylinder head (1), which rests on the liner (4) around the entire circumference of the compression chamber (8), the intake and exhaust ducts are sealed to the liner (4) by means of a sealant ( 6) in the grooves in which the non-milled parts of these canaries fit; the original valve seats (7) and other openings / canaries (eg spark plugs, injection nozzles) entering the compression chamber (8) are located directly in the insert (4), being fitted into the insert (4) in the same way as they were previously fitted to the cylinder head (1). A method of repairing a cylinder head of a reciprocating reciprocating machine according to claim 1, characterized in that a bore with a shoulder, i. j. on two different diameters (3). A method of repairing the cylinder head of a reciprocating reciprocating machine according to claim 1, characterized in that the sealing compound (6) of the insert (4) is replaced by a solder. A method of repairing the cylinder head of a reciprocating reciprocating machine according to claim 1, characterized in that the sealing compound (6) of the insert (4) is replaced by an O-ring in order to form a suitable groove in the insert (4). A method of repairing a cylinder head of a reciprocating reciprocating machine according to claim 1, characterized in that the intermediate canary through the insert (4) is sealed by a hollow bolt (9) which is sealed to a conical surface and screwed into an internal thread cut in the relevant channel, resp. at the transition point, in the cylinder head (1). 2 drawings