JPH04244936A - Method and apparatus for preparing engine main body - Google Patents

Abstract

PURPOSE:To accurately inspect the inferiority of a cylinder wall, a piston or a piston ring generating a gas leak during operation in an assembling process. CONSTITUTION:In such a state that the cylinder bore of a work B wherein a piston 2 and a crank shaft 3 are incorporated in a cylinder block is hermetically closed, air is introduced into the cylinder bore and the crank shaft 3 is gradually rotated to control the supply pressure of air to the cylinder bore at every definite crank angle so as to be approximate to the state at the time of the operation of an engine to measure an air leak and the inferiority of the work B is judged corresponding to the air leak state.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing an engine body, including inspection of workpieces during the assembly process.

0002

[Prior Art] Conventionally, for example, Japanese Patent Application Laid-Open No. 59-209974
As shown in the above publication, it is known to have a test line for inspecting manufactured engines. The test line and its transportation method shown in this bulletin are such that, during engine tests, various piping, etc. are connected to the engine on a pallet that supports and transports the engine, and then various tests are carried out while the engine is running. This is what I decided to do.

0003

[Problems to be Solved by the Invention] However, according to the conventional test equipment as described above, it is difficult to detect defects in the cylinder wall, piston, piston ring, etc. that may cause gas leakage between the cylinder wall and the piston of the engine. Difficult to detect accurately. Even if it is determined that there is a gas leak, it is difficult to analyze the circumstances under which the gas leak occurred and what kind of defect caused the gas leak.

The present invention solves the above-mentioned problem, and aims to solve the above-mentioned problems by removing cylinder walls, pistons,
It is an object of the present invention to provide a method for manufacturing an engine body and an apparatus therefor, which can accurately inspect for defects in piston rings, etc., and also enable analysis of defects.

[0005]

Means for Solving the Problems In order to achieve the above object, the present invention provides a method for manufacturing an engine body including a piston located in a cylinder bore and a crankshaft connected to the piston. ,
When the piston and crankshaft are assembled to the cylinder block, the work is inspected, and this inspection is carried out by supplying air from an air supply means to the cylinder bore with the cylinder bore of the work being sealed; Then, by gradually rotating the crankshaft and adjusting the supply pressure into the cylinder bore at each constant crank angle so that it is approximately equal to the pressure inside the cylinder bore at each crank angle during engine operation, It measures air leaks from inside the machine and determines whether the work is defective depending on the air leak situation.

[0006] In this method, the defects judged based on the air leak measurements in the above inspection are those in which air leaks of a predetermined value or more occur in all of the multiple measurements at a constant crank angle, and defects in which air leaks occur at a predetermined value or more only in some measurements. It is preferable to identify a defect in which an air leak is greater than a predetermined value, and to identify a defect in which an air leak in excess of a predetermined value occurs only in some measurements, based on the crank angle at the time the air leak occurs.

[0007] Furthermore, as an apparatus for carrying out the above method, a manufacturing apparatus for manufacturing an engine body including a piston located in a cylinder bore and a crankshaft connected thereto is equipped with an inspection apparatus for inspecting defects in a workpiece. The inspection device includes: an air supply means for supplying air under pressure to a workpiece in which a piston and a crankshaft are assembled to a cylinder block; a pressure adjustment means for regulating the pressure of the air supplied from the air supply means; a drive means for driving the crankshaft from the outside; and a drive means for controlling the drive means so as to gradually drive the crankshaft; and a drive means for controlling the drive means to drive the crankshaft gradually; A control means for controlling the pressure adjusting means so that the pressure is approximately equal to the pressure inside the cylinder bore at the crank angle, a leak detection means for detecting air leak from inside the cylinder bore, and an output of the leak detection means at each constant crank angle. and determining means for determining manufacturing defects of the workpiece.

[0008]

[Operation] According to the above configuration, the air leak from the cylinder bore is measured at every constant crank angle while the pressure supplied to the cylinder bore of the workpiece is adjusted to approximate the pressure during engine operation. By doing so, defects such as gas leaks during operation can be accurately investigated.

[0009]

[Embodiment] An embodiment of the present invention will be explained based on the drawings. FIG. 1 shows an inspection device A used for inspection in an assembly process when manufacturing an engine body. This inspection device A inspects a workpiece B in which a piston 2 and a crankshaft 3 are assembled to a cylinder block 1. The leak tester 10 constituting the means and leak detection means, and the crankshaft 3 of the work B
A workpiece servo motor 21 as a driving means for driving the
It also includes a master chamber 22 and a master chamber servo motor 26 for providing a reference pressure for detection by the leak tester 10, and a control unit 30 for control and defect determination. Further, a sealing jig 28 is prepared, and the workpiece B to be inspected by the inspection apparatus A is sealed by this sealing jig 28.

The leak tester 10 includes an air supply passage 11 communicating with the air pressure source 8, a pressure regulating valve 12, and a pressure sensor 13.
and a three-way valve 14, and a pair of branch passages 15, 16 connected to the air supply passage 11, an on-off valve 17,
18, and a differential pressure sensor 19 is connected between both the branch passages 15 and 16. Both branch passages 15 and 16 are connected to the workpiece B and the master chamber 22, respectively, and are supplied from the air pressure source 8 to the pressure regulating valve 1.
The air pressure regulated by 2 is supplied to the workpiece B and the master chamber 22, respectively. Then, after the air pressure is supplied, the on-off valves 17 and 18 are closed and held for a certain period of time, and the pressure difference between the work side and the master chamber side that occurs when air leaks from the work B is the above-mentioned differential pressure. It is detected by a sensor 19. In this way, the leak tester 10 constitutes a leak detection means, and the pressure regulating valve 12 included therein constitutes a pressure regulating means.

The workpiece servo motor 21 has its output shaft connected to the crankshaft 3 of the workpiece B, thereby rotating the crankshaft 3 of the workpiece B in response to a control signal. Further, the master chamber 22 is formed to have the same volume as the cylinder of the work B, and is equipped with a piston 23 and a crankshaft 24 similar to those of the work B, and a master chamber servo motor 26 is connected to the crankshaft 24. There is.

The control unit 30 controls each servo motor 21, 26 to rotate each crankshaft 3, 24 intermittently at a constant crank angle, and at each constant crank angle, each The pressure regulating valve 12 is controlled so as to supply the workpiece B and the master chamber 22 with a pressure that is substantially equivalent to the cylinder bore internal pressure at the crank angle. Furthermore, the three-way valve 14 and the on-off valve 17 are configured so that the leak tester 10 performs the leak detection operation as described above at each constant crank angle.
, 18, etc., and then determines whether the work B is defective based on the output of the differential pressure sensor 19. In this way, the control unit 30 constitutes a control means and a discrimination means.

[0013] An inspection method using this apparatus will be specifically explained. In the engine body assembly process, when the piston 2 and crankshaft 3 are assembled to the cylinder block 1, the work B is sent to the inspection device A, and for inspection, the work B is sealed by the sealing jig 28. At the same time, the leak tester 10 and the servo motor 21 are connected to the work B.

After completing such preparatory work, the servo motors 21 and 2 are activated by control signals from the control unit 30.
6 is controlled, the crankshaft 3 of the workpiece B is intermittently rotated by a constant crank angle, and the crankshaft 24 of the master chamber 22 is also rotated in the same way. On the other hand, at each constant crank angle, the air pressure is adjusted by the pressure regulating valve 12 so that it is approximately equal to the cylinder bore internal pressure at the crank angle during engine operation.
Air leak from inside the cylinder bore is measured based on the output of the differential pressure sensor 19 after a certain period of time after the on-off valves 17 and 18 are closed in this state.

As shown in FIG. 3, the air pressure supplied to the work B and the master chamber 22 is changed in accordance with the crank angle so as to substantially match the pressure change characteristics during engine operation. In other words, when ignition and combustion actually occur, ATDC 20° CA (ATDC means after top dead center, C
A indicates the crank angle), so such a characteristic is stored in advance in the control unit 30, and based on this, the above-mentioned supply air pressure is adjusted according to the crank angle. controlled.

In this manner, air leakage is measured at every constant crank angle in a state approximated to the engine operating state, and based on this, the air leakage situation is investigated by the control unit 30, and from this air leakage situation, it is determined that workpiece B is defective. The presence or absence of the defect is determined, and if a defect is determined, the type of defect, the location of the defect, etc. are determined. For example, when an air leak is measured above a predetermined value (standard value for determining a defect), it is determined to be defective. Analyze defects by identifying defects that cause air leaks that exceed the standard value only in some measurements, and examine the crank angle at the time the air leak occurs for defects that cause air leaks that exceed the standard value only in some measurements. Can be done.

Specifically, as shown in FIG. 3, for example, if an air leak exceeding the reference value (indicated by a dashed line) occurs at a crank angle at which the pressure inside the cylinder bore is at its maximum, the air leak will exceed the maximum pressure. This means that the piston ring cannot be completely prevented, so it is determined that the tension in the piston ring is insufficient. In addition, if the air leak occurs to the same degree at any crank angle as shown in Fig. 4, the material of the piston 2 may be defective, or the arrangement of the joints of the plurality of piston rings 4 attached to the piston 2 may be incorrect (Fig. 6), it is determined that the defect is such that gas leaks occur at all times regardless of the crank angle. In addition, if the air leak increases at crank angles other than the crank angle at which the maximum pressure occurs as shown in Figure 5, it may be due to cracks or pinholes in the cylinder bore 1a (see Figure 7), or poor straightness of the cylinder wall during honing. (See FIG. 8).

[0018] Such determination and analysis of defects may be reflected in the manufacturing process in a feedback manner. For example, in the case shown in Fig. 3 above, information based on the judgment is provided to the piston ring molding process, and in the case shown in Fig. 4, information based on the judgment is provided to the piston and piston ring forming and assembly processes. In case 5, information based on the determination is given to the honing process, and measures such as adjustment or material change can be taken in each process depending on the defect.

[0019]

As described above, according to the method according to claim 1, air is supplied to a workpiece in which a piston and a crankshaft are assembled to a cylinder block while the inside of the cylinder bore is sealed, and , by gradually rotating the crankshaft and adjusting the supply pressure into the cylinder bore at each constant crank angle so that it is approximately equal to the pressure inside the cylinder bore at each crank angle during engine operation, the pressure inside the cylinder bore is adjusted. Since air leaks from the cylinder are measured and defects are judged based on that, defects such as gas leaks from cylinders during operation can be accurately investigated during the assembly process, and the defects can be analyzed. is also possible.

In particular, as described in claim 2, there are two types of defects: a defect in which an air leak of a predetermined value or more occurs in all of a plurality of measurements at a constant crank angle, and a defect in which an air leak of a predetermined value or more occurs only in some measurements. In addition, for defects where air leaks exceeding a predetermined value occur only in some measurements, by examining the crank angle at the time the air leak occurred, it is possible to effectively analyze the type of defect and the location of the defect. , it is possible to efficiently take measures in response to defects in the manufacturing process.

Further, according to claim 3, there is provided an air supply means for a workpiece in which a piston and a crankshaft are assembled to a cylinder block, a pressure adjustment means for adjusting the air pressure, a drive means for the crankshaft, and a and a control means for controlling the pressure regulating means;
Since the above method is achieved by an inspection device including a leak detection means and a determination means for determining manufacturing defects of the workpiece based on the output of the leak detection means at each constant crank angle, the crankshaft in the above method is The above method can be carried out effectively by automatically rotating the air pressure, supplying and adjusting air pressure, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of an inspection device according to the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the air pressure supplied into the cylinder bore and the crank angle.

FIG. 3 is an explanatory diagram showing an example of an air leak situation.

FIG. 4 is an explanatory diagram showing another example of an air leak situation.

FIG. 5 is an explanatory diagram showing yet another example of an air leak situation.

FIG. 6 is a schematic diagram showing an example of a defect.

FIG. 7 is a schematic diagram showing another example of a defect.

FIG. 8 is a schematic diagram showing yet another example of failure.

[Explanation of symbols]

1 Cylinder block 2 Piston 3 Crankshaft 8 Pneumatic source 10 Leak tester 12 Pressure regulating valve 19 Differential pressure sensor 21 Servo motor for workpiece 30 Control unit

Claims (3)

[Claims] Claim 1: In a method of manufacturing an engine body including a piston located in a cylinder bore and a crankshaft connected thereto, the workpiece is inspected at the stage when the piston and crankshaft are assembled to a cylinder block. This inspection is carried out by supplying air into the cylinder bore from the air supply means with the cylinder bore of the workpiece sealed, and gradually rotating the crankshaft to inject air into the cylinder bore at constant crank angles. The system adjusts the supply pressure so that it is approximately equal to the pressure inside the cylinder bore at each crank angle during engine operation, measures the air leak from inside the cylinder bore, and determines whether the work is defective depending on the air leak situation. A method for manufacturing an engine body, characterized in that: Claim 2: Regarding defects determined based on air leak measurements in the above inspection, there are defects in which air leaks are greater than a predetermined value in all of multiple measurements at a constant crank angle, and defects in which air leaks are greater than a predetermined value only in some measurements. 2. The method according to claim 1, further comprising: identifying a defect in which an air leak occurs, and further identifying a condition of a defect in which an air leak exceeding a predetermined value occurs only in some measurements based on the crank angle at the time of occurrence of the air leak. The manufacturing method of the engine body. 3. A manufacturing device for manufacturing an engine body including a piston located in a cylinder bore and a crankshaft connected to the piston, comprising an inspection device for inspecting a workpiece for defects, the inspection device including a piston in a cylinder block and a crankshaft connected thereto. and an air supply means for supplying air under pressure to a workpiece to which the crankshaft is assembled, a pressure adjustment means for regulating the pressure of the air supplied from the air supply means, and an air supply means for externally driving the crankshaft. a drive means, and the drive means is controlled to gradually drive the crankshaft, and the pressure supplied to the cylinder bore at each constant crank angle is approximately equal to the cylinder bore internal pressure at each crank angle during engine operation. A control means for controlling the pressure regulating means so as to be equal to each other, a leak detection means for detecting air leak from inside the cylinder bore, and a manufacturing defect of the workpiece is determined based on the output of the leak detection means at every fixed crank angle. 1. A manufacturing apparatus for an engine body, comprising: a determining means.