JPH051610Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a compression engine brake device.
In particular, it relates to improvements to systems that operate valve bodies during engine braking, and is effective for use in vehicles equipped with a compressed air (hereinafter referred to as air) source, such as trucks. .

[Conventional technology]

As a conventional compression engine brake device, a dedicated valve body is provided in the cylinder chamber of a diesel engine in addition to the intake valve and exhaust valve, and this valve body is a hydraulic cylinder device whose driving source is the movement of an exhaust cam. When engine braking is desired, the valve body is opened by a hydraulic cylinder device near the top dead center of the engine's compression stroke, and the compression energy of the engine is released. Some are configured to vent and perform an engine braking action.

[The problem that the idea aims to solve]

In such a compression engine brake device, since a hydraulic cylinder device is used, there is a problem that the structure becomes complicated.

An object of the present invention is to provide a compression engine braking device whose structure can be simplified.

[Means to solve the problem]

In the compression engine braking device according to the present invention, a valve body 4 separate from the intake valve and exhaust valve of the diesel engine 1 is provided in the cylinder head 2 of the diesel engine 1 so as to communicate with the cylinder chamber 3 of the exhaust valve. The valve body 4 is installed in a valve seat 12 formed around a valve port 11 formed at a connection point of the exhaust path 5 with the engine cylinder chamber 3, and is seated on and off the valve seat 12. A cylinder chamber 14 is formed in the cylinder head 2 around a valve stem 13 that is integrally connected to the valve body 4 so as to protrude to the side opposite to the engine cylinder chamber 3. A piston 15 is located inside the cylinder chamber 14.
The cylinder chamber 14 is slidably moved forward and backward relative to the engine cylinder chamber 3 so as to partition the cylinder chamber 14 into a second chamber 14b on the side of the engine cylinder chamber 3 and a first chamber 14a on the opposite side from the engine cylinder chamber 3. In the compression engine brake device that is fitted, the cylinder chamber 14 is formed as an air cylinder chamber, the first chamber 14a of the air cylinder chamber 14 is connected to the first supply path 18, and the second chamber 14b is connected to the second chamber through the first supply path 18. They are respectively connected to the air supply sources 10 via supply passages 19, and an electromagnetic control valve 20 is interposed in the middle of the second supply passage 19. port 2
1. It is equipped with a second port 22 on the second chamber 14b side and a third port 23 that communicates with the atmosphere. Under normal conditions, the first port 21 and the second port 22 communicate with each other, and the third port 23 is closed. Further, the first port 21 is closed at a predetermined time, and the second port 22 is communicated with a third port 23, and the solenoid 24 of the electromagnetic control valve 20 is energized when an engine brake operation is desired. The device is characterized in that the device is configured to perform the switching operation.

[Effect]

Normally, air is supplied to the first and second chambers on both sides of the piston through the first supply path and the second supply path, so the valve body is closed.

When the engine brake is desired to be applied, when the second chamber is communicated with the atmosphere by the control valve, the piston is moved by the air in the first chamber, and the valve body is opened, so that compression is compressed from the engine cylinder chamber. Due to the energy being discharged, an engine braking action will be performed.

In this way, since the valve body is controlled by the air cylinder device, the structure can be simplified.

〔Example〕

FIG. 1 is a schematic diagram showing a compression engine brake device which is an embodiment of the present invention.

In this embodiment, the compression engine brake device according to the present invention is configured to be applied to a diesel engine installed in a vehicle equipped with an air brake system, such as a truck, and has an intake valve and an exhaust valve (see Fig. (not shown). This valve body 4 is installed in the cylinder head 2 of a diesel engine (hereinafter simply referred to as the engine) 1 and its cylinder chamber 3 (only a portion of which is shown).
The exhaust passage 5 is connected to an air tank 6 at the other end. The air tank 6 is an air supply source 10 in an air brake system (not shown).
A check valve 8 is interposed in the supply path 7 to allow only flow from the supply source 10 to the air tank 6. A relief valve 9 is connected to the supply path 7, and the pressure of the relief valve 9 is set so as to maintain the pressure at which the air tank 6 can perform a supercharging action, which will be described later.

A valve port 11 is opened at a connection point of the exhaust passage 5 with the engine cylinder chamber 3, and a valve seat 12 is formed around the valve port 11 toward the engine cylinder chamber 3 side. The valve body 4 is provided to open and close the valve port 11 by seating on and leaving the valve seat 12 from the inside.
They are integrally connected so as to protrude to the opposite side. The cylinder head 2 has an air cylinder chamber 14 disposed near the engine cylinder chamber 3, and a piston 15 inside the air cylinder chamber 14.
is fitted into the engine cylinder chamber 3 so as to be slidable in the direction of advancing and retreating. A seal ring 16 is arranged around the outer periphery of the piston 15 and is fitted into the piston 15 .
is partitioned into a chamber 14b on the side of the engine cylinder chamber 3 (hereinafter referred to as the second chamber) and a chamber 14a on the side opposite to the engine cylinder chamber 3 (hereinafter referred to as the first chamber). Also, the piston 1 is removed from the second chamber 14b.
A valve spring 17 is installed in the gap extending over the opening of 5.
3a, a spring seat plate 13b, and a valve stem 13, the valve body 4 is biased and fitted so as to be always seated on the valve seat 12, and the valve stem is attached to the center of the back surface 15a of the piston head. The end portion 13c of 13 can come into contact with it.

The first chamber 14a of the air cylinder chamber 14 is connected to the first supply passage 18, and the second chamber 14b is connected to the second supply passage 19.
are respectively connected to the air supply source 10 via the second supply path 19, and a control valve 20 is interposed in the middle of the second supply path 19. The control valve 20 has 3 ports, 2 positions,
It is configured as a PA connection, spring offset, and electromagnetic switching valve, and includes an air supply source side port (hereinafter referred to as the first port) 21, a second chamber 14b side port (hereinafter referred to as the second port) 22, and the atmosphere A port (hereinafter referred to as a third port) 23 is provided which communicates with the port. In normal times, the first port 21 and the second port 22 communicate with each other, and the third port 23 is closed, and in a predetermined time, the first port 21 is closed and the second port 22 communicates with the third port 23. The control valve 20 is configured to be communicated with. The solenoid 24 of the control valve 20 is configured to be energized to perform a switching operation when the engine brake is desired to be activated.The solenoid 24 of the control valve 20 is configured to be energized to perform a switching operation when an engine brake operation is desired. ).

Next, the action will be explained.

During normal operation of the diesel engine 1, the first control valve 20 in this compression engine braking device
Since the port and the second port 22 are in communication with each other, air from the air supply source 10 flows through the first supply path 18 and the second supply path 19 to the air cylinder chamber 14.
Both chambers 14a and 14 of piston 15 in
b. Therefore, in this state,
The pressures on both sides of the piston 15 are balanced.

When a situation in which engine braking is desired is detected, such as when the accelerator pedal is suddenly released, the control valve 20 is switched by operating the solenoid 24 under the control of the controller. By this switching operation, the first port 21 of the control valve 20 is closed and the second port 22 is connected to the third port 23, so that the second chamber 14b of the air cylinder chamber 14 is connected to the second supply path 19 and the control valve. 20 to the atmosphere. On the other hand, since air is supplied to the first chamber 14a of the air cylinder chamber 14 through the first supply path 18, the piston 15 is
Due to the pressure in the chamber 14a, it is moved toward the second chamber 14b against the biasing force of the spring 17. piston 1
5 is moved, the valve body 4 connected by the valve stem 13 is unseated from the valve seat 12 and opens the valve port 11.

When the timing at which the valve port 11 is opened by the valve body 4 is controlled by the controller so as to be near the top dead center in the compression stroke of the diesel engine, a piston (not shown) is activated in the engine cylinder chamber 3. The compressed air is discharged from the valve port 11 to the air tank 6 through the exhaust path 5.
By discharging the compressed air during this compression stroke,
In the diesel engine 1, compression energy is consumed and no explosion occurs, so
Engine braking will be performed very effectively.

On the other hand, in this embodiment, a part of the compressed air (hereinafter sometimes referred to as air) discharged during engine braking is stored in the air tank 6 at a set pressure. Then, at the beginning of the compression stroke of the diesel engine during normal operation of the diesel engine 1, the control valve 20 is switched under the control of a preset controller, and the valve body 4 is operated.
When the engine opens the valve port 11, the air at the set pressure stored in the air tank 6 is supercharged into the engine cylinder chamber 3 through the exhaust path 5 and the valve port 11. continue,
As the compression stroke in the engine cylinder chamber 3 progresses, the pressure in the cylinder chamber 3 increases, but before reaching the set pressure, the controller operates the control valve 20 to close the exhaust passage 5. In this way, the cycle of supercharging ends and this operation is repeated during the supercharging period.

Incidentally, when the air pressure stored in the air tank 6 decreases due to supercharging during supercharging operation, air for the air brake system is replenished from the air supply path 7 to the air tank via the check valve 8.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be modified without departing from the gist thereof.
It goes without saying that various changes are possible.

For example, the exhaust path for discharging compressed air from the engine cylinder chamber is not limited to being connected to the air tank, but may be opened to the atmosphere.

[Effect of idea]

As explained above, according to the present invention, the valve body for discharging compression energy is opened and closed by an air cylinder device, which greatly simplifies the structure compared to the case where a hydraulic cylinder device is used. In addition to being able to perform supercharging with this device, the effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a compression engine brake device which is an embodiment of the present invention. 1... Diesel engine, 2... Cylinder head, 3... Engine cylinder chamber, 4... Valve body,
5... Exhaust path, 6... Air tank, 7... Air supply path, 8... Check valve, 9... Relief valve, 10...
...Air supply source, 11...Valve port, 12...Valve seat, 1
3...Valve stem, 14...Air cylinder chamber, 14a...
...First chamber, 14b...Second chamber, 15...Piston, 16...Seal ring, 17...Spring, 18...First supply path, 19...Second supply path,
20... Control valve, 21, 22, 23... Port,
24...Solenoid.

Claims (1)

[Scope of Claim for Utility Model Registration] A valve body 4 separate from the intake valve and exhaust valve of the diesel engine 1 is opened in the cylinder head 2 of the diesel engine 1 so as to communicate with the cylinder chamber 3 of the exhaust passage 5. The valve element 4 is seated on and off the valve seat 12 formed around the valve port 11, which is formed at the connection point of the exhaust passage 5 with the engine cylinder chamber 3, to open the valve port 11. The cylinder head 2 is configured to open and close, and the cylinder chamber 14 is formed around a valve stem 13 that is integrally connected to the valve body 4 so as to protrude to the side opposite to the engine cylinder chamber 3. A piston 15 is located in the cylinder chamber 14.
The cylinder chamber 14 is slidably moved forward and backward relative to the engine cylinder chamber 3 so as to partition the cylinder chamber 14 into a second chamber 14b on the side of the engine cylinder chamber 3 and a first chamber 14a on the opposite side from the engine cylinder chamber 3. In the compression engine brake device that is fitted, the cylinder chamber 14 is formed as an air cylinder chamber, the first chamber 14a of the air cylinder chamber 14 is connected to the first supply path 18, and the second chamber 14b is connected to the second chamber through the first supply path 18. They are respectively connected to the air supply sources 10 via supply passages 19, and an electromagnetic control valve 20 is interposed in the middle of the second supply passage 19. port 2
1. It is equipped with a second port 22 on the second chamber 14b side and a third port 23 that communicates with the atmosphere, and normally, the first port 21 and the second port 22 are communicated, and the third port 23 is closed. ,Also,
At a predetermined time, the first port 21 is closed and the second port 22 is communicated with the third port 23, and the solenoid 24 of the electromagnetic control valve 20 is energized to perform a switching operation when an engine brake operation is desired. A compression engine braking device configured to perform.