JPS6237946Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fuel injection timing control device for an engine of an automobile or the like.

Conventionally, in order to improve the operating efficiency or exhaust gas components of an engine, the fuel injection pump used in the engine changes its fuel injection timing depending on the operating state of the engine, and the change is mainly caused by the hydraulic actuator. This is done by operation, but the hydraulic actuator is one that directly operates a phase angle conversion device that controls the relative rotational phase angle between the engine output shaft and the drive shaft of the fuel injection pump, and one that is linked. However, in the latter, it is difficult to eliminate play in the link system, whereas in the former, the hydraulic actuator and the phase angle converter are integrated. Since there is no play in the system, it has the advantage of making it easy to ensure high control responsiveness. However, in the former case, since the hydraulic actuator is installed inside the rotating body, it is necessary to communicate pressure oil to the hydraulic actuator through a rotary joint. requires careful consideration.

An object of the present invention is to provide a fuel injection timing control device in which the phase angle conversion device and the hydraulic actuator are integrated as described above, and the rotary joint is constructed with high durability and at low cost.

To explain the present invention based on an embodiment, FIG. 1 shows a side sectional view of a fuel injection timing control device as an embodiment of the present invention, and FIG. 2 shows a cross section in FIG. 1. It is something that

In FIG. 1, the input shaft 2 enclosing the output shaft 3 is fastened to a side plate 2b by a plurality of bolts 6, and the integrated input shaft 2 and side plate 2b are attached to a bearing 1.
Casing 1 and side plate 1 via b and 1c
The side plate 1a is fastened to the casing 1 by bolts (not shown).

The output shaft 3 has a sleeve 2d fitted onto the input shaft 2.
A male helical spline 3a cut into the output shaft 3 forms a spline with a twisted groove in the axial direction of the output shaft 3. The female spline 2g is a normal spline parallel to the axial direction of the output shaft 3.

Male helical spline 3a and female spline 2g
A slider 4 is fitted into the annular portion of the slider 4 so as to be able to slide in the axial direction, and a male spline 4a and a female helical spline 4b are cut into the slider 4.
are configured to fit into the female spline 2g and the male helical spline 3a, respectively.

An annular piston portion 4e fixed to the slider 4 is slidable in the axial direction into an annular cylinder 4f constituted by a sleeve 2k fitted to the input shaft 2 and a sleeve 2e fitted to the side plate 2b. possible mating. A hole 2h formed in the input shaft 2 communicates with an end surface 4d of the slider 4, while a hole 2i formed in the input shaft 2 communicates with an end surface 4c of the piston portion 4e.

The rotary joint 5 fixed to the casing 1 is attached to the casing 1 when the casing 1 is cast.
As shown in Fig. 2, the rotary joint 5 has a
The output shaft 3 has a protrusion 5c in the radial direction, and the protrusion 5c is formed by cutting an end surface 5e exposed to the outside of the casing 1. A hydraulic valve 8 is screwed onto the end surface 5e, and the protrusion 5c is cut into the rotary joint 5. One of the holes 5d communicates with the annular groove 5a, and the annular groove 5b, which is also cut in the rotary joint 5, has a protrusion 5c drilled in the same way as the hole 5d. The perforations (not shown) are in communication with each other, and one perforation 5d and the other perforation (not shown) are connected to the groove 5.
It is configured to communicate with the perforations 2h and 2i via a and 5b, respectively.

The hydraulic valve 8 alternately and selectively communicates each of the hydraulic pipes 7a and 7b with one of the perforations 5d and the other, or with the other perforation and one perforation 5d, or with one perforation 5d and the other perforation. The operation is configured to selectively close the communication in the perforation, and the command for this operation is transmitted through the signal line 9e.
The calculation is performed by the calculator 9 via the .

7 is a hydraulic pump incorporating a relief valve, 10 is a reservoir, 9c and 9d are signal lines, and 9a and 9b are electromagnetic pickups in FIG. 1, respectively.

The gear 2a fitted on the input shaft 2 is a part that takes in rotational power from the engine.
An electromagnetic pick-up 9a provided close to the circumference of
is for electrically detecting the rotation speed and rotation angle of the input shaft 2, and a disc 3b fitted on the output shaft 3 has one or more protrusions 3c cut in the circumferential direction. 9b is the same electromagnetic pickup as 9a.

Further, 1d is an oil seal, 2f is a perforation, and 2c is a gear that drives the hydraulic pump 7.

To explain the operation of the configuration shown in FIGS. 1 and 2 above, when the input shaft 2 is driven by the engine (not shown), the power is transferred to the gear 2a, the input shaft 2, and the female spline 2g. , the slider 4, the male helical spline 3a, and the output shaft 3 drive a fuel injection pump (not shown) coupled to the output shaft 3.

In this state, the input shaft 2 is driven by gear coupling with the engine, so the electromagnetic pick-up 9a that detects the rotational speed and rotation angle of the gear 2a detects them on the drive shaft of the engine. It is the same as that. On the other hand, the electromagnetic pickup 9b that detects the rotation angle of the output shaft 3 detects the displacement of the relative rotation phase angle with respect to the rotation angle of the input shaft 2, and these detected values are calculated at each engine rotation speed. , is calculated by the calculator 9 so that the fuel injection pump injects fuel from the most appropriate rotation angle, and the resulting output voltage (analog quantity) or output pulse voltage (digital quantity) from the calculator 9 is connected to the signal line. The hydraulic valve 8 is actuated via 9e, and the hydraulic valve 8 outputs a hydraulic pressure corresponding to the output voltage or the output pulse voltage to one of the boreholes 5d or the other borehole.

Here, the hydraulic valve 8 becomes a proportional control valve when the voltage signal on the signal line 9e is an analog quantity, and becomes an on/off control valve when the voltage signal is a digital quantity.

In the above-described operation, when a hydraulic pressure is applied to one of the boreholes 5d and the other borehole (not shown) is opened to the reservoir 10, the hydraulic pressure is applied to the slider 4 through the groove 5a and the borehole 2h. On the other hand, the pressure oil on the end surface 4c side is released to the reservoir 10 through the hole 2i, the groove 5b, the other hole and the hydraulic valve 8. As a result, the slider 4 is pushed to the right by the hydraulic pressure, and at this time, the female spline 2g forms a spline groove parallel to the axial direction of the output shaft 3, while the male helical spline 3a Since it forms a spline groove twisted obliquely with respect to the axial direction of the output shaft 3,
When the slider 4 moves to the right, the rotational phase angle of the output shaft 3 relative to the input shaft 2 increases.

Since this state in which the rotational phase angle increases is constantly detected by the electromagnetic pickups 9a and 9b, when the rotational phase angle reaches the programmed rotational phase angle corresponding to the rotational speed of the engine, the hydraulic valve 8 is closed, and as a result, the movement of the slider 4 in the axial direction also stops.

Contrary to the above operation, when the rotational phase angle of the output shaft 3 with respect to the input shaft 2 is decreased in accordance with the engine rotation speed, the hydraulic pressure is sent to the other perforation, and the one perforation 5d is connected to the reservoir 10. opened to
By pressing the end face 4c side, the hydraulic pressure moves the slider 4 to the left, and the movement stops when the rotational phase angle programmed in the calculator 9 corresponding to the engine rotational speed is reached. This is the same as the explanation above.

In the above operation description, in order to change the rotational phase angle, the female spline 2g side may be a helical spline and the male helical spline 3a side may be a normal spline, or both of the above splines may be all helical splines. .

Also, by reversing the use of input shaft 2 and output shaft 3,
Even if the output shaft 3 is driven by the engine and the input shaft 2 is used to drive the fuel injection pump, the same results will be obtained relatively.

As is clear from the above description, the fuel injection timing control device of the present invention has a rotary joint 5 made of a metal material with bearing capacity welded to a casing 1 made of an aluminum alloy material, and a pressure oil communication passage of the perforation 5d. Since the projection 5c is made to protrude in the radial direction of the rotary joint 5, due to the rotational sliding resistance generated between the rotational peripheral surface 2j of the input shaft 2 and the rotary joint 5, Even if the rotary joint 5 tries to rotate, the protrusion 5c reliably prevents the rotation, and there is no need for any other structure such as a pin to prevent the rotation. Therefore, the structure is made inexpensive and suitable for mass production.

Note that this rotation is prevented because the casing 1 and the rotary joint 5 have different coefficients of thermal expansion, so the welding between the casing 1 and the rotary joint 5 becomes loose during long-term use. This is a necessary configuration in order for this to occur.

Furthermore, the fuel injection timing control device according to the present invention has one of the perforations 5d and the protrusion 5c forming the other perforation exposed to the outside of the casing 1, and a hydraulic valve 8 provided in the one perforation 5d and the other perforation. Since the hydraulic passages are configured to communicate directly with each other, the pressure oil in the communication leaks between the weld surfaces of the casing 1 and the rotary joint 5, and the pressure caused by the pressure oil separates the weld. There is no play between the casing 1 and the rotary joint 5, and there is no fear that pressure oil will leak outside.

[Brief explanation of the drawing]

FIG. 1 shows a side sectional view of a fuel injection timing control device as an embodiment of the present invention, and FIG. 2 shows a side sectional view of FIG. 1. The symbols used in the examples are as follows.
1: Casing, 1a: Side plate, 1b and 1c:
Bearing, 1d: Oil seal. 2: Input shaft, 2a:
Gear, 2b: side plate, 2c: gear, 2d, 2e and 2k: sleeve, 2f, 2h and 2i: perforation, 2g: female spline, 2j: rotating peripheral surface. 3:
Output shaft, 3a: male helical spline, 3b: disc, 3c: protrusion. 4: slider, 4a: male spline, 4b: female helical spline, 4c and 4d: end face, 4e: piston portion, 4f: cylinder. 5: Rotary joint, 5a and 5
b: groove, 5c: protrusion, 5d: perforation, 5e: end surface.
6: Bolt, 7: Hydraulic pump, 7a and 7b:
Hydraulic pipe, 8: Hydraulic valve, 9: Calculator, 9a and 9
b: Electromagnetic pickup, 9c, 9d and 9e:
Signal line. 10: Reservoir.

Claims (1)

[Claims for Utility Model Registration] 1. Between the input shaft that interlocks with the engine and the output shaft that drives the fuel injection pump, there is a shaft that controls the relative rotational phase angle between the input shaft and the output shaft. A hydraulic actuator that rotates integrally with the input shaft and the output shaft is provided, and a rotary joint that communicates the control oil to the hydraulic actuator surrounds the input shaft or the output shaft in the rotational circumferential direction. , the rotary joint is welded to a casing that pivotally supports at least one of the input shaft and the output shaft, and has a protrusion in the normal direction to the rotational circumferential direction of the rotary joint, and the protrusion includes: A perforation is provided to communicate between the hydraulic actuator and a hydraulic valve that controls the flow of the pressure oil to be force-fed to the hydraulic actuator, and the protrusion is exposed from the casing portion. A fuel injection timing control device characterized by: 2 The configuration in which the protrusion is exposed from the casing is
The fuel injection timing control device according to claim 1, wherein the exposed portion of the protrusion has an end face cut and a hydraulic valve is screwed onto the end face.