JP2607495Y2 - Hydraulic timer start advance device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a start-up advance device for a hydraulic timer which sends hydraulic pressure from an engine-driven oil pump to a hydraulic timer actuator via an advance control valve to control the advance angle of an injection pump. Things.

[0002]

2. Description of the Related Art There has been known a start-up advance device of a hydraulic timer which sends the oil pressure of an oil pump driven by an engine to a hydraulic timer actuator via an advance control valve to control the advance angle of an injection pump. However, as a problem of such a hydraulic timer, there is a problem that the engine does not advance when the oil pressure is hardly increased at the time of starting the engine, that is, the startability at low temperatures is deteriorated.

[0003] Accordingly, the applicant has filed a Japanese Utility Model Application No. 62-1.
Japanese Patent No. 69232 discloses a technique in which a hydraulic pump with a bypass is provided in a hydraulic circuit leading to a hydraulic timer, and the hydraulic pump is operated at startup. Although this technique is effective, it has a drawback that it is complicated and expensive, such as interposing an electric pressurizing pump on the hydraulic supply side. Further, Japanese Utility Model Laid-Open Publication No. Sho 59-182643 discloses a technique relating to a hydraulic timer advancing device in which a hydraulic pump for power steering is shared and a hydraulic pump dedicated to a hydraulic timer is eliminated. This technique includes a technique of assisting with an accumulator until the hydraulic timer actuator reaches a sufficiently high pressure state. However, this technique does not accumulate pressure in advance and optimize the timer advance angle at startup.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed to address the above-mentioned problems of the prior art.
It is not an expensive and complicated structure with an electric pressurized pump, etc., but can easily secure the amount of advance at the time of low-temperature start and optimize the advance of the hydraulic timer. It is intended to provide.

[0005]

According to the present invention, the hydraulic pressure from the engine-driven oil pump (3) is sent to the hydraulic timer actuator (2) via the advance control valve (5), and the injection pump (1) is operated. ), The oil pump (3) and the oil pan (4) are connected to a suction tube (1).
4), the advance control valve (5) comprises an ADV valve (6) and a RET valve (7), and the oil pump (3) is connected to the ADV valve (6) via an oil tube (8). And the ADV valve (6) and RE
The oil valve (9) is connected to the T valve (7),
An oil tube (11) branched from the oil tube (9) is connected to a timer actuator (2), and is connected to an air tank (17) and a diaphragm type actuator (1).
3) is connected by an air circuit (L2) via a three-way valve (15), and the diaphragm actuator (13)
Is an oil chamber (13) on the opposite side of the air chamber (13b) to which the air circuit (L2) is connected by the diaphragm (13c).
a), and the oil chamber (13a) is provided with a hydraulic circuit (L
1) is connected to the branched oil tube (11), and the three-way valve (15) is configured to close during rotation of the engine and to open immediately after starting the engine.

According to the present invention, the hydraulic pressure from the oil pump (3) driven by the engine is sent to the hydraulic timer actuator (2) via the advance control valve (5), and the advance angle of the injection pump (1) is adjusted. In the starting advancement device of the hydraulic timer to be controlled, the oil pump (3) and the oil pan (4) are connected by a suction tube (14),
The advance control valve (5) comprises an ADV valve (6) and a RET valve (7), and the oil pump (3) is connected to the ADV valve (6) via an oil tube (8). The valve (6) and the RET valve (7) are connected by an oil tube (9), and an oil tube (11) branched from the oil tube (9) is connected to a timer actuator (2) to form a hydraulic accumulator (20). The oil chamber (21) is connected to an on-off valve (18) via an oil tube (19), and the hydraulic accumulator (20) has a diaphragm (23) inside the high-pressure gas chamber (22) and the oil chamber. The on-off valve (18) is connected to an oil tube (11), and is closed when the engine is running continuously, Off valve immediately after the engine is started and (1
8) is configured to open.

[0007]

According to the first embodiment of the hydraulic timer provided with the diaphragm-type actuator constructed as described above, the supply oil has a high viscosity at a low temperature. At the time of starting the engine where a sufficient increase in hydraulic pressure cannot be obtained by the pump, high-pressure air is supplied from a pre-filled air tank to a diaphragm actuator via a three-way valve, and the diaphragm actuator controls the advance angle via a second circuit. The oil pressure is transmitted to the oil tube connecting the valve and the hydraulic timer actuator, and the hydraulic timer actuator can be immediately and appropriately advanced.

Further, according to the starting advancement device of the hydraulic timer to which the hydraulic accumulator configured as described above is connected (second invention), the hydraulic pressure stored in the hydraulic accumulator at the time of starting the engine. Is transmitted to the oil tube connecting the advance control valve and the hydraulic timer actuator via the opening / closing valve, and similarly, it is possible to immediately advance the angle appropriately. According to the above (first or second) invention, optimization of the advance angle at the time of starting at a low temperature can be achieved with a simple configuration without providing a special pressurizing pump, a switching valve, and the like.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, an oil pump 3 and an oil pan 4 driven by an engine (not shown) are connected by a suction tube 14. The pressure oil discharged from the oil pump 3 passes through the oil tube 8 and the ADV valve 6
And the RET valve 7 are introduced into the ADV valve side 6 of the advance control valve 5.

The ADV valve 6 and the RET valve 7 are connected by an oil tube 9, and the RET valve 7 and the oil pan are connected by an oil tube 10.
And the oil tube 1 branched from the oil tube 9
1 is connected to the timer actuator 2.

On the other hand, the air tank 17 and the diaphragm actuator 13 are connected via a three-way valve 15 by an air circuit L2 constituting a first circuit. The inside of the diaphragm type actuator 13 is divided by a diaphragm 13C into an oil chamber 13a on the left side in the drawing and an air chamber 13b on the right side. The oil chamber 13a is connected to the oil tube 11 by a hydraulic circuit L1 constituting a second circuit.

FIG. 1 shows a state where the engine is continuously rotating and the three-way valve 15 is closed, so that the air pressure is cut off. FIG. 2 shows a state immediately after the start of the engine. The three-way valve 15 is opened, air pressure is applied to the diaphragm 13b, and the oil in the oil chamber 13a transmits the pressure to the timer actuator 2 via the circuit L1.

In FIG. 3, an oil chamber 21 of a hydraulic accumulator 20 and an on-off valve 18 are connected by an oil tube 19. The hydraulic accumulator 20 has an upper part connected to an upper high-pressure gas chamber 22 and a lower part by a diaphragm 23. And an oil chamber 21. And the on-off valve 1
8 is connected to the oil tube 11. In addition,
FIG. 3 shows a state where the engine is continuously rotating,
Since the on-off valve 18 is closed, the high-pressure gas is cut off. FIG. 4 shows a state immediately after the start of the engine. The on-off valve 18 is opened, a high-pressure gas pressure is applied to the diaphragm 23, and the oil in the oil chamber 21 is supplied to the oil tube 1.
9. Transmit the pressure to the timer actuator 2 via the circuit L1.

[0014]

[Effect of the Invention] The present invention is configured as described above.
The following effects are obtained. (A) According to the starting advancing device of the hydraulic timer provided with the diaphragm type actuator (invention according to claim 1), the viscosity of the supplied oil is high at a low temperature, and therefore a sufficient oil pressure increase can be obtained by the oil pump. Even when the engine is not started, the hydraulic timer actuator can be immediately and appropriately advanced with the help of the high-pressure air in the air tank that has been filled in advance. (B) Further, according to the starting advancement device of the hydraulic timer to which the hydraulic accumulator is connected (invention according to claim 2),
At the time of starting the engine, the hydraulic pressure stored in the hydraulic accumulator is supplied to the hydraulic timer actuator, and the angle can be immediately advanced properly. (C) According to the inventions of claims 1 and 2, optimization of the advance angle at the time of starting at a low temperature can be achieved with a simple configuration without providing a special pressurizing pump, a switching valve, and the like, and Good responsiveness. (D) Further, since the working pressure is directly supplied to the hydraulic timer actuator, the operation is quick, and it is only necessary to add components upstream from the hydraulic circuit L1 with respect to the prior art, so that the improvement is simple. (E) According to the invention of claim 1, since an air tank for a brake can be used, installation and change of an existing device are easy.

[0015]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of the overall configuration during rotation of an engine according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a partial configuration of the first embodiment of the present invention at the time of starting advance angle operation.

FIG. 3 is a schematic diagram illustrating a partial configuration of an engine during rotation according to a second embodiment of the present invention.

FIG. 4 is a schematic view showing a partial configuration of a second embodiment of the present invention at the time of starting advance operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Injection pump 2 ... Timer actuator 3 ... Oil pump 4 ... Oil pan 5 ... Advance control valve 6 ... ADV valve 7 ... RET valve 8, 9, 10, 11 ... Oil tube 13 ... Diaphragm actuator 13a ... Oil chamber 13b ... Air chamber 13c ... Diaphragm 15 ... Three-way valve 17 ... Air tank 18 ... On-off valve 19 ...・ Oil tube 20 ・ ・ ・ Hydraulic accumulator 21 ・ ・ ・ Oil chamber 22 ・ ・ ・ High pressure gas chamber 23 ・ ・ ・ Diaphragm L1 ・ ・ ・ Hydraulic circuit (second circuit) L2 ・ ・ ・ Air circuit (First circuit) )

Claims (2)

(57) [Scope of request for utility model registration] A hydraulic timer for sending hydraulic pressure from an engine-driven oil pump (3) to a hydraulic timer actuator (2) via an advance control valve (5) to control the advance of an injection pump (1). In the starting advancing device of
The oil pump (3) and the oil pan (4) are connected by a suction tube (14), and the advance control valve (5) comprises an ADV valve (6) and a RET valve (7). 3) is an oil tube (8)
And connected to the ADV valve (6) through the
The V valve (6) and the RET valve (7) are connected by an oil tube (9), and the oil tube (11) branched from the oil tube (9) is connected to the timer actuator (2), and the air tank (17) The diaphragm type actuator (13) is connected by an air circuit (L2) via a three-way valve (15), and the diaphragm type actuator (13) is connected to an air circuit (L2) by a diaphragm (13c). (13b) and an oil chamber (13a) on the opposite side.
a) is connected to the branched oil tube (11) by a hydraulic circuit (L1), and the three-way valve (15) is configured to be closed while the engine is running and to be opened immediately after the engine is started. Characteristic starter for hydraulic timer. 2. A hydraulic timer for sending hydraulic pressure from an engine-driven oil pump (3) to a hydraulic timer actuator (2) via an advance control valve (5) to control the advance of the injection pump (1). In the starting advancing device of
The oil pump (3) and the oil pan (4) are connected by a suction tube (14), and the advance control valve (5) comprises an ADV valve (6) and a RET valve (7). 3) is an oil tube (8)
And connected to the ADV valve (6) through the
The V valve (6) and the RET valve (7) are connected by an oil tube (9), and an oil tube (11) branched from the oil tube (9) is connected to a timer actuator (2) to form a hydraulic accumulator (20). ), The oil chamber (21) is connected to the on-off valve (1) via an oil tube (19).
8) connected to said hydraulic accumulator (20)
The inside is separated by a diaphragm (23) into a high-pressure gas chamber (22) and the oil chamber (21), the on-off valve (18) is connected to an oil tube (11), and the engine rotates continuously. The on-off valve (18) is closed when the engine is running, and the on-off valve (18) is opened immediately after starting the engine.