JP2008038909A - Transfer pump for high-pressure petrol injection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for solving problems such as noise and wear of components, since, in some engines, there is a need to mount a high-pressure direct injection pump in an end of a camshaft or above a pulley of a transmission, and not directly in a cylinder head. <P>SOLUTION: The transfer pump for high-pressure petrol injection is a type provided with a piston 10 sending out hydraulic liquid into a deformable bellows 14. In the transfer pump, deformation of the bellows 14 in a cylindrical chamber filled with fuel causes an effect of supplying the fuel at a high pressure, and a cam 5 provided with a lobe 6 is supported by a crankshaft 1. Wholes of mechanical portions of driving and crank mechanisms are immersed in oil of an oil portion of the transfer pump. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a high-pressure gasoline injection pump having a piston for sending hydraulic fluid into a deformable part such as a bellows, and the deformation of the bellows in a cylindrical chamber filled with fuel is applied to the high-pressure injection device. The present invention relates to an improvement of a high-pressure gasoline injection pump that produces an action of supplying the fuel.

This type of pump is described in French Patent Application No. 2826068, French Patent Application No. 28828240 and the specification of French Patent Application No. 06/02594 by the present applicant. .
French Patent Application Publication No. 2826068 French Patent Application Publication No. 28828240

  The present invention aims to provide a solution to two problems arising from mounting this type of pump on an engine.

The first problem arises from the fact that some engines require that a high pressure direct injection pump be mounted on the end of the camshaft or transmission pulley rather than directly on the cylinder head.
When using a mono-piston pump, a crank mechanism is required, which increases the size of the pump and various inconveniences such as the need for an adjustment casing, lubrication, noise, wear of parts, etc. Is caused.

The second problem arises from the fact that such an installation requires, for example, an Oldham coupling type actuator set between the pump drive and the pump.
When the pump is a mono-piston, large fluctuations in the resistance torque of the pump occur, sometimes with a negative peak, which can cause the contact surface transmitting the torque to separate, which can cause cranking. A source of torque return into the shaft.
These torque returns constitute elements that impede engine operation, such as irregular torque changes in the camshaft or timing chain, unacceptable noise, and the like.

The solution to the first problem consists of envisioning the pump such that the oil part includes not only the pump part but all the drive and crank mechanism parts.
This eliminates, in part, the dynamic airtightness that moves over mono-piston transfer pumps, which are very long and difficult to control. As an advantage, it is lubricated.
Furthermore, the increase in the sealed volume of the oil improves the holding time of the oil and reduces the risk of overheating.
The solution to the second problem consists of placing a one-way clutch between the crankshaft and the cam.

That is, the means for solving the problems of the present invention are as follows.
First,
A high-pressure gasoline injection transfer pump comprising a piston (10) for sending hydraulic fluid into a deformable bellows (14),
The deformation of the bellows (14) in the cylindrical chamber (20) filled with fuel gives rise to the action of supplying the fuel at high pressure, and the cam (5) with lobes (6) is connected to the crankshaft (1 In the transfer pump supported by
The oil portion of the transfer pump includes a portion of the crankshaft (1) that supports the cam (5), a cam (5), a lobe (6), and a support component (12) that allows the shaft (8) and needle bearing ( 9) includes a roller (7) supported together and a cam (5) supported on the piston (10), and an upper portion of the piston (10);
As a result, the entire mechanical part of the drive and crank mechanism is immersed in the oil of the oil part.
Second,
The transfer pump according to claim 1, characterized in that the airtightness between the oil part and the crankshaft (1) is ensured by a single lip seal (30).
Third,
The transfer pump according to claim 1 or 2, characterized in that an annular chamber (21) of a casing (3) in which a cam (5) is housed is connected to a second volume compensator (26). .
Fourth,
A second volume compensator (27) is connected to the sliding intermediate part (22), and within the sliding intermediate part (22), the roller (7), the support component (12) and the piston (10). The transfer pump according to the third aspect, wherein the upper part moves.
Fifth,
The piston (10) includes a piston internal intermediate portion (10a) having a backflow prevention valve (28) communicating with the sliding intermediate portion (22) by an orifice (24), so that the pressure is increased. The transfer pump according to the fourth aspect, wherein the volume of the oil is very small.
Sixth,
The piston (10) slides in the hollow shaft (13) provided with a disc (17) having a hollow shaft inner middle portion (19) at the bottom, and the inside of the hollow shaft inner middle portion (19) When the finger-like member (18) supported by the annular part (15) fixed to the bottom of the bellows (14) slides and thereby the bellows (14) continuously deforms, the bellows (14) The transfer pump according to claim 5, wherein the transfer pump is reliably guided.
Seventh,
The transfer pump according to the first aspect, wherein the drive mechanism of the crankshaft (1) is a one-way clutch.

  According to the present invention, since the entire mechanical part of the drive and crank mechanism is immersed in the oil of the oil part, problems such as noise and wear of parts can be solved.

The present invention is illustrated by way of non-limiting examples and for ease of understanding in the following accompanying drawings.
FIG. 1 is a cross-sectional view of one embodiment of a transfer pump according to the present invention.
2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a partial view illustrating a modification of FIG.

  Referring to these drawings, the transfer pump according to the present invention includes a crankshaft 1 connected to an unillustrated driving component (for example, a camshaft) by an Oldham coupling 2.

  The crankshaft 1 is supported by a casing 3.

The crankshaft 1 supports a cam 5.
This cam 5 comprises four lobes 6 in the illustrated embodiment.

The piston 10 supports the cam 5 by a return spring 11.
A roller 7 supported by a shaft 8 via a needle bearing 9 is interposed between the piston 10 and the cam 5.

Preferably, the support part 12 is arranged between the roller 7 and the piston 10.
This support part 12 is advantageously constituted by two recesses 12 a, 12 b which are opposite to each other and separated by a partition wall 12 c comprising a plurality of orifices 23.

The outer wall of the support part 12 is provided with a penetration part.
By providing the penetration portion, the passage of oil around the support component 12 is facilitated.

  The piston 10 supported by the return spring 11 slides in the hollow shaft 13.

The end 13 a of the hollow shaft 13 penetrates into the bellows 14.
The bellows 14 includes an annular component 15 supported by a return spring 16 at the lower end.

A disk 17 is disposed inside the hollow shaft 13 and at the end of the hollow shaft 13.
The disc 17 has a hollow shaft internal centering portion 19 at the center.
The finger-like member 18 supported at the center by the annular part 15 slides inside the hollow shaft inner middle part 19.
This ensures that the bellows 14 is accurately guided when the bellows 14 extends continuously.
The bellows 14 is configured to move inside the cylindrical chamber 20.
Therefore, by securing a guide for the bellows 14, the diameter of the cylindrical chamber 20 can be reduced and optimally adjusted.
The cylindrical chamber 20 is filled with fuel.

  FIG. 1 shows that the cam 5 rotates inside an annular chamber 21 provided inside the casing 3.

An annular chamber 21, a roller 7, a support part 12, and a sliding intermediate part 22 in which the upper part of the piston 10 slides, a piston internal intermediate part 10 a that is an internal intermediate part of the piston 10, and the interior of the hollow shaft 13 The hollow shaft internal intermediate portion 19 that is the intermediate portion and the inside of the bellows 14 are filled with hydraulic fluid.
This hydraulic fluid passes around the support component 12.
Further, the hydraulic fluid passes through the partition wall 12 a through the orifice 23.
Next, the hydraulic fluid enters through the orifice 24 into the piston internal intermediate portion 10 a inside the piston 10, and passes through the disk 17 through the orifice 25.

  This ensures good communication between the various parts filled with oil.

In this way, the volume of oil supplied continuously can be made considerably large.
As a result, the oil has a longer holding time and the risk of overheating is reduced.

  In order to prevent the pulse operation that may occur due to the movement of the lobe 6 of the cam 5, it may be advantageous to arrange a first volume compensator 26 in communication with the annular chamber 21 in which the cam 5 moves (FIG. 1).

  For the same reason, it is possible to arrange a second volume corrector 27 that communicates with the feeding section 22 during sliding (FIG. 2).

  A backflow prevention valve 28 is disposed inside the piston 10 inside the piston 10a.

As a result, only the intermediate portion 29 of the piston internal intermediate portion 10a located downstream of the backflow prevention valve 28 is pressurized.
Therefore, only a small volume of oil is pressurized, while the remaining volume of oil is not pressurized.
When the piston 10 is re-raised by the action of the return spring 11, the communication is restored between the pressurized oil and the entire remaining oil that has not been pressurized.

  This helps prevent oil overheating.

The crankshaft 1 is driven by a one-way clutch.
Therefore, the irregular change transmitted to the cam 5 is not transmitted to the crankshaft 1.

  The oil tightness of the oil part of the pump is ensured by a single lip seal 30 disposed between the crankshaft 1 and the casing 3.

  All the components of the drive machine part, i.e. the cam 5, the roller 7 and the needle bearing 9, and the support part 12 which slides in the sliding section 22 are immersed in oil and are completely lubricated.

  FIG. 3 shows a modified embodiment at the top of FIG. 2 illustrating the drive mechanism of the cam 5.

  In this drawing, the same symbols are attached to the same elements.

  In this embodiment, the cam 5 is a single part integrated with the crankshaft 1, and the transmission using the Oldham coupling 2 includes a one-way clutch.

The portion forming the cam 5 includes a cylindrical cylindrical recess 32.
A cylindrical cylindrical shaft 31 is fitted inside the recess 32.
A guide component is interposed between the cylindrical shaft 31 and the inner wall of the recess.

A bearing 4 that supports the crankshaft 1 is disposed outside the casing 3.
A single lip seal 30 that maintains hermeticity is located between the bearing 4 and the cam 5 inside the casing 3.

  In this embodiment, the bearing 4 is not lubricated by hydraulic fluid, but is lubricated by engine oil.

It is sectional drawing of one embodiment of the transfer pump by this invention. It is sectional drawing by the AA line of FIG. FIG. 3 is a partial view illustrating a modification of FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Oldham coupling 3 Casing 4 Bearing 5 Cam 6 Robe 7 Roller 8 Shaft 9 Needle bearing 10 Piston 10a Piston internal part 11 Return spring 12 Supporting part 12a Recess 12b Recess 12c Partition wall 13 Hollow shaft 13a End 14 Bellows 15 annular part 16 return spring 17 disk 18 finger-like member 19 hollow shaft internal middle part 20 cylindrical chamber 21 annular chamber 22 sliding middle part 23 orifice 24 orifice 25 orifice 26 first volume corrector 27 second volume corrector 28 Backflow prevention valve 29 Intermediate feed portion 30 Single lip seal 31 Cylindrical cylindrical shaft 32 Cylindrical cylindrical recess

Claims (7)

A high-pressure gasoline injection transfer pump comprising a piston (10) for sending hydraulic fluid into a deformable bellows (14),
The deformation of the bellows (14) in the cylindrical chamber (20) filled with fuel gives rise to the action of supplying the fuel at high pressure, and the cam (5) with lobes (6) is connected to the crankshaft (1 In the transfer pump supported by
The oil portion of the transfer pump includes a portion of the crankshaft (1) that supports the cam (5), a cam (5), a lobe (6), and a support component (12) that allows the shaft (8) and needle bearing ( 9) includes a roller (7) supported together and a cam (5) supported on the piston (10), and an upper portion of the piston (10);
As a result, the entire mechanical part of the drive and crank mechanism is immersed in the oil of the oil part.   Transfer pump according to claim 1, characterized in that the airtightness between the oil part and the crankshaft (1) is ensured by a single lip seal (30).   Transfer pump according to claim 1 or 2, characterized in that the annular chamber (21) of the casing (3) containing the cam (5) is connected to the second volume compensator (26). .   The second volume compensator (27) is connected to the sliding part (22), and inside the sliding part (22), the roller (7), the support part (12), and the piston (10). The transfer pump according to claim 3, wherein the upper part moves.   The piston (10) includes a piston internal intermediate portion (10a) having a backflow prevention valve (28) that communicates with the sliding intermediate portion (22) by an orifice (24), and is thus pressurized. The transfer pump according to claim 4, wherein the volume of the oil is very small.   The piston (10) slides in the hollow shaft (13) provided with a disc (17) having a hollow shaft internal middle portion (19) at the bottom, and the inside of the hollow shaft inner middle portion (19) When the finger-like member (18) supported by the annular part (15) fixed to the bottom of the bellows (14) slides and thereby the bellows (14) continuously deforms, the bellows (14) The transfer pump according to claim 5, wherein the transfer pump is reliably guided.   Transfer pump according to claim 1, characterized in that the drive mechanism of the crankshaft (1) is a one-way clutch.

Images