JPS63131836A - Dash pot for engine - Google Patents

Abstract

PURPOSE:To intensity early damper action and advance the completion period of operation by defining a liquid chamber at the compression and non- compression sides of a casing cylinder and providing a check valve in a communicating hole of a piston while providing a tapered path on the slide surface of a cylinder. CONSTITUTION:A piston 25 is inserted into a casing cylinder 24 to define liquid chambers 27, 28. The piston 25 is formed with a communicating hole 29, and a check valve 30 is provided which closes the communicating hole 29 in compression. Further, the casing cylinder 24 is provided on the slide surface with a path 34 tapered in the direction of compression of piston. Thus, a powerful damper force can be obtained while the completion period of operation can be advanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dashpot that adjusts the closing speed of a throttle valve during deceleration of an engine.

(Prior Art) There is a dashpot that prevents an increase in unburned gas (HC) by slowing down the closing speed of a throttle valve when decelerating an engine (see Japanese Patent Laid-Open No. 51-41131, etc.).

To explain this as shown in FIG. 14, the throttle body 1
When the throttle valve 2 on the primary side installed in the engine is suddenly closed due to deceleration, etc., the shaft 7-3 of the throttle valve 2 hits the stem (0) 5 of the dashpot 4 at a certain opening degree. , the air chamber 7 in the dashbot 4 is compressed by the diamond 7 ram 6 connected to the stem 5. The pressurized air in the chamber 7 gradually flows out of the air chamber 7 while encountering resistance through the vent hole 8 provided in the dial 7 ram 6, and in conjunction with this, the throttle valve 2 gradually opens. close.

In this way, the throttle valve 2 is gradually closed to alleviate sudden negative pressure changes in the intake air W9, thereby suppressing fluctuations in the supplied air-fuel mixture, thereby preventing an increase in unburned gas during deceleration, etc. It is supposed to be done.

In addition, 10 is a check valve that opens when the shaft arm 3 separates from the stem 5 to let air into the air chamber 7, and 11 is a check valve that sets the opening degree of the throttle valve 2 at which the shaft arm 3 starts touching the stem 5. Set nut, 12 is 2
This is the next throttle valve.

(Problems to be Solved by the Invention) However, in such a conventional dashbot 4, air, which is a compressible fluid, is used, and the vent hole 8 of the diamond 7 ram 6 that produces the gunpa effect is fixed. Therefore, it is not always possible to obtain good operating characteristics suitable for the engine.

Fig. 15 shows the operation characteristics. For example, in the conventional dashbot 4, after the shaft arm 3 comes into contact with the stem 5, there is an idle running section until the pressure in the air chamber 7 increases. settings are likely to be incorrect.

In addition, since the force of air is weak, the gunba effect is insufficient. Therefore, at the beginning of the operation when the shaft arm 3 hits the stem 5 with force, the closing speed of the throttle valve 2 is fast and the change in negative pressure is alleviated. Not done. Therefore, ttS
As shown in Figure 16 and Figure fjS18, the amount of air supplied to Schilling suddenly decreases, and the air-fuel ratio (A/F) of the mixture temporarily decreases.
exceeds the rich limit. During deceleration, etc., the supply of fuel from the fuel injection valve etc. decreases rapidly, but at the beginning of deceleration, a large amount of fuel remains in the intake pipe as shown in FIG. 17, and this is sucked into the cylinder.

Furthermore, Figures 15, 16, and 18 show the characteristics with a conventional dashpot [A] and the characteristics without a dashpot [A].
[mouth]] and the required characteristics [c].

On the other hand, because the ventilation holes 8 provided in the dashbot 4 are fixed, the conventional dashbot ends its operation late, which seriously impairs the feeling of deceleration, and if the gear is set to neutral during this operation. , which may lead to an increase in engine speed.

Furthermore, since the force of the dashpot 4 is weak, it is necessary to use a large dashbot 4, which causes problems in terms of space when attaching it to the throttle body 2.

The object of the present invention is to provide a hydraulic dashbot that solves these problems.

(Means for Solving the Problems) The present invention includes a rod that is interlocked with a throttle valve installed in an intake pipe of an engine from a predetermined opening degree via a shaft arm, and a rod that is connected to the rod and that moves the inside of a casing cylinder at a predetermined opening angle. A piston that can slide in the gap is provided to define liquid chambers on the piston compression side and non-compression side of the casing cylinder, and a check valve is provided to close the communication hole provided in the piston during compression. A passage is provided in the dynamic surface from a predetermined position in a tapered shape in the piston compression direction.

(Function) Therefore, when the shaft arm hits the rod, the piston compresses the liquid chamber, so it immediately starts to work as a gunpa, and a strong gunba action can be obtained from the initial stage of operation. Furthermore, since the tapered passage is formed on the sliding surface of the casing cylinder, the resistance is weakened as the piston moves in the compression direction, thereby shortening the time at which the operation ends.

(Example) This shows an example of the fpJ1 drawing to the 3rd design of the 2nd drawing.
0 is a throttle body, 21 is a shaft arm connected to a rotating shaft 22 of a throttle valve (not shown), and 2
3 is a dashpot.

In the dashpot 23, a piston 25 is slidably interposed within a casing cylinder 24 with a predetermined gap, and the piston 25 is connected to a rod 26 that passes through an end surface of the casing cylinder 24.

Liquid chambers 27 and 28 are defined in the casing cylinder 24 on both sides of the piston 25, and each of the liquid chambers 27 and 28 is filled with oil (for example, silicone oil).

A communication hole 29 for the liquid chambers 27 and 28 is formed in the piston 25, and a check valve 30 is attached to the piston 25 to close the communication hole 29 when the liquid chamber 27 is compressed.

Further, a predetermined spring 31 is provided in the liquid chamber 27 to urge the piston 25 toward the liquid chamber 28 .

32 is a cover, and 33 is an oil seal.

A tapered passage (groove) 34 whose passage area gradually increases from a predetermined position in the direction of compression of the piston 25 is formed on the sliding surface of the casing cylinder 24.

Although not shown, when the liquid chamber 27 is compressed, the rod 26
The liquid chamber 2
8 is connected to an oil reservoir. Also, dashpot 23
is from the predetermined opening degree of the throttle valve to the shaft arm 2.
so that the bolt 35 attached to 1 hits the rod 26,
It is arranged on the throttle body 20, and the contact point can be adjusted by means of the bolt 35.

With this configuration, when the bolt 35 of the shaft arm 21 hits the rod 26 and the piston 25 is pushed toward the liquid chamber 27 due to sudden closing of the throttle valve, the check valve 30 closes and the oil in the liquid chamber 27 is removed. is compressed, but since oil is an incompressible fluid, there is no idle running section after the shaft arm 21 makes contact, unlike in the conventional example.

Therefore, the operation start point of the dashpot 23 can be easily and accurately set using the bolt 35.

Then, the compressed oil in the liquid chamber 27 is transferred to the piston 2.
5 and the casing cylinder 24 through the sliding gap to the liquid chamber 28 side, but as it is compressed, it immediately starts to act as a gunpah and creates strong resistance due to the oil.
Sufficient damping action is ensured from the initial stage of operation. Therefore, at the beginning of deceleration when the shaft arm 21 hits the rod 26 with force, the closing speed of the throttle valve is adjusted to Pt515.
As shown in [C] in the figure, the amount can be reduced reliably as required.

Therefore, it is possible to prevent the throttle valve from having a high jump speed and adversely affecting the air-fuel ratio as in the conventional example, and to suppress the sudden decrease in air amount as shown in [C] in Figs. 16 and 18. The air-fuel ratio can always be kept within the appropriate range.

Also, a piston 25 is provided on the sliding surface of the casing cylinder 24.
Since the groove 34 is tapered in the direction of compression of the liquid chamber 2,
7, the resistance to oil leakage becomes weaker, which shortens the time when the dashpot 23 completes its operation (
[C] in Figure 15).

This ensures a good sense of deceleration, and even if the gear is set to neutral in the later stages of operation of the dashpot 23, an increase in engine speed can be avoided.

Furthermore, since the dashpot 23 using oil has a strong force as a goomba, its structure can be made sufficiently small, so it does not require a large space unlike the conventional example, and the throttle body 20 etc. The degree of freedom of installation is significantly increased.

4 to 7 show another embodiment of the present invention, in which instead of using oil as the working fluid of the dashpot 36, Ennon cooling is sent from the engine cooling system to the throttle body 20 to prevent icing. It is designed to use water.

This engine cooling water flows from the inlet boat 37 into the cooling water passage 38 in the throttle body 2 (), and then flows into the outlet boat 3
The cooling water passage 38 flows out from the passages 40 to 4.
2 to the liquid chambers 43 and 44 of the dashpot 36. In this case, a liquid chamber 43 is located in the middle of the passage 40.
A ball valve 45 that closes when compressed is provided, and a relief valve 46 that opens when the pressure inside the chamber 43 exceeds an upper limit is provided in the middle of the passage 41.

Therefore, when the piston 25 moves and the liquid chamber 43 is compressed, the ball valve 45 closes to ensure the same damping effect as in the previous embodiment, while the cooling water removed by the volume of the rod 26 is removed from the liquid chamber 43. from the side into the passageway 42. Furthermore, when the operation of the dashpot 36 is completed, the ball valve 4
5 is opened, and cooling water is supplied from the passage 40 to the liquid chamber 43. Note that the maximum pressure within the liquid chamber 43 is kept constant by the relief valve 46.

In this way, engine cooling water is always supplied to the dashpot 36 as the working fluid, so even if the working fluid leaks from the seal, the predetermined goomba function can be maintained at all times, and maintenance is easy. It becomes 7 Lee.

In addition, when the temperature or antifreeze concentration of cooling water changes, the density, viscosity, etc. of the cooling water change, which may affect the damper action. Therefore, even if the temperature etc. changes, the same damper characteristics can always be obtained.

Note that if a filter 47 is interposed between the cooling water passage 38 and each of the passages 40 to 42, it is possible to prevent dust and the like from entering the liquid chambers 43 and 44, and also to prevent the collected dust and the like from entering the liquid chambers 43 and 43.
．． The filter 47 can be purged by the cooling water returned from the filter 44 .

8 to 10 show another embodiment of the present invention using oil as the working fluid, in which the casing cylinder 48
The passage area of the passage 49 formed on the sliding surface of is made variable.

In this case, the casing cylinder 48 is formed into a somewhat tapered shape on the liquid chamber 50 side, and has a thinner wall thickness, and is provided with predetermined protrusions 51 above and below the outer periphery of the end thereof.

A bushing 52 is fitted onto the end of the casing cylinder 48 from the outside via a tapered inner circumferential surface 53, and the bushing 52 is movable by a screw 54.

Note that 55 is an oil reservoir communicating with the liquid chamber 50 through a gap with the end of the casing cylinder 48, 56 is an accumulator, and 57 is an oil seal.

According to this, by screwing in the bushing 52, the casing cylinder 48 becomes flat as shown in FIGS. The passage area of the passage 49 formed in the surface is variable.

That is, by changing the position of the pushbutton 52, the closing speed of the throttle valve can be arbitrarily set as shown in FIG. Even if variations occur, they can be easily adjusted and set to predetermined damper characteristics.

(Effects of the Invention) As described above, the present invention defines liquid chambers on the piston compression side and non-compression side of the casing cylinder, and is provided with a check valve that closes a communication hole provided in the piston during compression. The sliding surface of the dashpot has a tapered passage in the direction of piston compression, which ensures a strong damping force for the liquid and provides a damper action that meets the engine's requirements, resulting in excellent performance as a dashpot. can get.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing embodiments of the present invention and A-A
li sectional view and configuration diagram, FIGS. 4 to 7 are sectional views showing other embodiments of the present invention, B-B#l sectional view, configuration diagram, and bottom view thereof, and FIGS. 8 to 10 11 is a sectional view, a sectional view taken along the line C-C, and a side view showing another embodiment of the present invention, FIGS. 15 to 18 are graphs showing operating characteristics, air amount, fuel amount, and air-fuel ratio characteristics. 21... Shaft arm, 24... Casing cylinder, 25... Piston, 26... Rod, 27
．． 28...Liquid chamber, 29...Communication hole, 30...Check valve, 34...Passage, 43.44...Liquid chamber, 48
...Casing cylinder, 49...Passage, 50...
・Liquid chamber. Patent applicant Nissan Motor Co., Ltd. agent Patent attorney Masaki Goto (1 other person) Figure 1 Figure 2 25: Jin x Toz 30:
Chi r+y7fP26: O-v de
x:nxFigure 3zj Do r3 0ri lDoFigure 4
□53 Figure 6 Figure 8 Figure 9 Time Figure 14

Claims (1)

[Claims] The throttle valve installed in the intake pipe of the engine is equipped with a rod that is linked to the throttle valve from a predetermined opening degree via a shaft arm, and a piston that is connected to the rod and can slide within the casing cylinder with a predetermined gap. Liquid chambers are defined on the compression side and non-compression side of the piston, and a check valve is provided to close a communication hole provided in the piston during compression. An engine dashpot featuring a passageway.