JPH0324616B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a device for measuring maximum cylinder pressure of an internal combustion engine. Conventional technology The conventional cylinder maximum pressure measuring device attaches a maximum pressure gauge to the other end of the manual knob attached to the end of the passage communicating with the combustion chamber, opens the manual knob each time a measurement is made, and then reads the pressure gauge's indication. The scale is read when the maximum value is reached, and this operation is repeated for each cylinder. Such conventional measurement methods have the following drawbacks. ) Skilled personnel is required when installing. ) If the maximum pressure gauge is permanently installed in the engine, the pressure gauge will become extremely hot, which is dangerous, and the durability of the pressure gauge will also be compromised. ) Since the pressure gauge becomes hot in a multi-cylinder engine,
There is a danger if measurements are not taken quickly. ) The operations during measurement are as follows: attaching the pressure gauge → opening the handle → measuring → closing the handle → opening the pressure relief valve (exhaust valve) → closing the pressure relief valve → removing the pressure gauge. Even if it is done, a considerable amount of measurement time is required. In addition, if there is a change in the load condition of the engine during measurement, it is necessary to repeat the measurement from the beginning, which takes even longer measurement time. ) Errors tend to occur in reading the scale of the pressure gauge. Purpose of the Invention This invention aims to eliminate the above-mentioned conventional drawbacks, and aims to save labor and speed up the measurement of the maximum pressure inside a cylinder, improve stability, and improve the durability of the pressure gauge. The object of the present invention is to provide a device for measuring the maximum pressure inside a cylinder. Structure of the Invention In order to achieve the above object, the present invention includes a remotely controllable first valve installed at the end of a passage communicating with the combustion chamber for each cylinder to be measured, and a first valve connected to the outlet side of the first valve in the direction of the combustion chamber. a check valve that allows gas to flow only from the check valve; a remotely controllable second valve that is connected to the outlet side of the check valve and has one side open to the atmosphere; and a second valve that is interposed between the check valve and the second valve. Maximum pressure inside a cylinder, characterized by comprising a pressure transducer configured to output the pressure of combustion gas acting on a pressure receiving part via a diaphragm as an electric signal, and a control device that operates the above-mentioned remote control valve. The present invention provides a measuring device. Effects This invention has the effects listed below by having the above configuration. ) Complicated operations are controlled by programs built into the control device, so there is no need for experienced personnel at all, resulting in significant labor savings, and there is no need to operate in high-temperature and high-pressure areas. Therefore, there is no danger. ) Since the pressure transducer is open to the atmosphere via the second valve except during measurement, there is no problem with the durability of the pressure transducer during measurement, and the pressure receiving part of the pressure transducer is directly connected via the diaphragm. Since it does not come into contact with combustion gas, it does not become hot and is safe, and there are no problems with durability. ) Since the pressure transducer outputs electrical signals, various processing such as digital display and printout of measurement data is possible, and unattended measurements including scheduled measurements are possible. Embodiments Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings. As shown in Figure 1, in a four-cylinder internal combustion engine,
Each combustion chamber 1 (1A, 1B, 1
Passage 2 (2A, 2B, 2
The first valve 3 (3A, 3
B, 3C, 3D) are installed, and a check valve 4 (4
A, 4B, 4C, 4D) are installed, and piping 5 (5A, 5B, 5
C, 5D) are connected to one common pipe 6, a diaphragm device 7 for pressure detection is attached to one end of the pipe 6, and a second valve 8 which is remotely operated is attached to the other end. The exit passageway is open to the atmosphere. The diaphragm device 7 is connected to a pressure transducer 9 that outputs detected pressure as an electric signal, and sends the output electric signal to a control device 10. Also,
The remote-controlled first valves 3 (3A to 3D) are operated by a pneumatic source 1 so as to be operated by a pilot air system.
1 and the first solenoid valve 13 (13
A to 13D) are operated by the control device 10 to
Pressure air is supplied to the valve 3 to open the first valve 3, and the second valve 8 is similarly connected to the air pressure source 11 via a pipe 14, and a second solenoid valve 15 is interposed in the pipe. The second solenoid valve 15 is operated by the control device 10 to supply pressurized air to the second valve 8, thereby closing the second valve 8. The first valve 3 (3A to 3D), the check valve 4 (4A
~4D), the second valve 8 and the pressure transducer 9 have the structure shown in FIG. That is, the first valve 3 has a pressure air introduction hole 17 that communicates with the pipe 12 in the upper end wall 16a of the cylinder 16 in the vertical direction in the drawing, and introduces pressurized air into the air chamber 18 in the cylinder 16 through the hole 17. That's what I do. A piston 20 biased upward by a spring 19 is slidably fitted into the air chamber 18, and the upper end of a shaft-shaped valve 21 is fixed to the center of the upper end of the piston 20 via a nut 22. .
The valve 21 slidably passes through a shaft hole 23 communicating with the air chamber 18 of the cylinder 16, and a valve cover 21a provided at the lower end of the valve 21 approaches and separates from a valve seat 24 formed at the lower end of the shaft hole 23 to open and close. I try to do that. The lower side of the valve seat 24 is a combustion gas chamber 25, which communicates with the passage 2 through a passage 26 bored in the lower cylinder wall 16b, and the shaft hole 23 above the valve seat 24 is made larger than the valve 21. A combustion gas passage 27 is formed as a diameter, and the combustion gas is introduced into the combustion gas passage 27 when the valve is opened. In addition, a cooling water chamber 28 is provided on the outer periphery of the passage 26 in the lower cylinder part 16b, and cooling water is introduced through a cooling water inlet 29 similarly bored in the lower wall and drained through a cooling water outlet 30. The combustion gas passing through passage 26 is cooled. Further, a non-contact pressure seal 31 is attached to the outer periphery of the valve 21 that slides on the shaft hole 23, and a non-contact pressure seal 32 is also attached to the outer periphery of the piston 20 to seal the combustion gas. A check valve connection port 33 is formed in the cylinder side wall in communication with the upper end of the passage 27, and the left end 4a of the check valve 4 is fitted into the connection port 33 to be directly attached without piping. However, it may be installed via piping. The check valve 4 has passages 38 and 39 communicating with the chambers 36 and 37 on both the front and rear sides in the valve box 35, and a valve body operating chamber 40 in the center between the passages 38 and 39. There is. Further, a passage 41 communicating with the connection port 33 of the first valve 3 is provided in the front chamber 36, and a valve seat 42 is formed in the connection part, and the valve is slidably fitted in the valve body operating chamber 40. The body 43 is the valve seat 42
It opens and closes when it comes into contact with the The valve element 43 is fitted with a conical end portion 44a of a pusher member 44 having a cross-shaped cross section that is slidably fitted into the valve member operating chamber 40, and the pusher member 44 is screwed into the valve member operating chamber 40. Press with a spring 46 compressed between the set screw 45 and the set screw 45,
The valve body 43 is urged in the closing direction. The check valve 4
The rear chamber 37 communicates with the piping 5, and the connection port 33
More combustion gas flows into the setting screw 45 and spring 4.
6, when the valve opening pressure is reached or higher, the valve body 43 opens, enters the rear chamber 37 through the passages 38 and 39, enters the common piping 6 from the rear chamber 37 through the piping 5, and flows into the diaphragm device 7. At the same time, it flows into the second valve 8 side. In the diaphragm device 7, one side 51a of a chamber 51 partitioned by a diaphragm 50 communicates with the piping 6 via a passage 52, the other side 51b communicates with the pressure transducer 9 via a passage 53, and a diaphragm is connected to the passage 53. An enclosing material 54 is enclosed which is displaced in accordance with the displacement of 50. The second valve 8 is provided with a substantially L-shaped passage 61 on the lower wall of the cylinder 60, one end of which communicates with the piping 6 and the other end of which is open to the atmosphere, and a valve seat 6 formed in the middle of the passage 61.
The lower conical valve body portion 63a of the shaft-shaped valve 63 approaches and separates from the shaft-shaped valve 63 to open and close. The valve 63 is
A piston 66 that is biased by a spring 65 and slidably fitted into an air chamber 64 provided above the cylinder 60
The upper end is attached via a nut 67. The air chamber 64 communicates with the passage 14 through a pressurized air hole 68 formed in the upper wall of the cylinder. Above 6
Non-contact pressure seals 69 and 70 are attached to the outer periphery of the piston 3 and the piston 66, respectively. The first solenoid valve 13 that supplies pressurized air from the air pressure source 11 to the air chamber 18 of the first valve 3 is a 3-port, 2-position switching spring offset solenoid valve type, as shown in FIG. When the chamber 18 is opened to air and a valve opening signal is issued from the control device 10 during measurement, the solenoid 13-1 is activated and the switching operation is performed.
The air chamber 18 communicates with the air pressure source 11 so that pressurized air is introduced into the air chamber 18. Similarly, the second solenoid valve 15 that supplies pressurized air from the air pressure source 11 to the air chamber 64 of the second valve 8 is a 3-port, 2-position switching spring offset solenoid valve type as shown in FIG. The air chamber 64 is opened to the atmosphere, and pressurized air is introduced during measurement. As shown in FIG. 5, the control device 10 includes a microcomputer unit (hereinafter referred to as CPU) 82 of the intermediate processing device that controls various units, and signals for opening and closing the first and second solenoid valves 13 and 15. Digital output (hereinafter referred to as D/
(hereinafter referred to as A/D) 83, an analog-to-digital converter (hereinafter referred to as A/D) 8 that digitally converts the pressure electrical signal (analog value) obtained by the pressure converter 9
4. A read-only memory (hereinafter referred to as
ROM (hereinafter referred to as ROM) 85, random access memory (hereinafter referred to as RAM) 86 for writing pressure data, and interface (hereinafter referred to as
(referred to as I/F) 87. Next, the operation of measuring the maximum pressure inside the cylinder using the above-mentioned device will be explained. The following pressure measurement sequence is written in the ROM 85 of the control device 10, and operations are performed in the order of A→D shown in FIG.

[Table] ↓

Claims (1)

[Claims] 1. A first valve that can be remotely operated is installed in a passage communicating with the combustion chamber of the cylinder, and a check valve is provided that is connected to the outlet side of the first valve and allows gas to pass only from the direction of the combustion chamber. , a second valve that can be remotely operated via piping is provided on the outlet side of the check valve, a passage end of the second valve is opened to the atmosphere, and piping is provided between the check valve and the second valve. A pressure transducer that detects the pressure of combustion gas and outputs an electric signal is interposed in the first valve and the second valve.
A device for measuring maximum pressure in a cylinder of an internal combustion engine, comprising a control device that opens and closes a valve. 2. An internal combustion system characterized in that the pressure receiving part of the pressure transducer according to claim 1 does not come into direct contact with the combustion gas through the diaphragm, and is opened to the atmosphere through the second valve when not measuring. A device that measures the maximum pressure inside an engine cylinder.