JP2002089412A - Fitting structure of injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fitting structure of an injector capable of positioning an annular seal member relative to the axial direction of the injector without lowering the strength and enlarging the size of the injector. SOLUTION: The injector 12 is installed in a fitting hole 11a opened in a combustion chamber R provided in a cylinder head 11 via a seal member 18. A cylindrical portion 18a of the seal member 18 is interposed in a first clearance G1 between the internal circumferential face of the insertion hole 11b constituting the fitting hole 11a and the outer circumferential face of a nozzle portion 14 connected to the body 13 of the injector 12, and a flange portion 18b formed in the seal member 18 is interposed in a third clearance G3 between a tapered bottom face 11d constituting the fitting hole 11a and the bottom face of a fastening member 17 fixing the nozzle portion 14 to the body 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injector mounting structure for an engine, and more particularly, to a cylinder head constituting an engine main body and an injector mounting structure fixed to the head for supplying fuel to a combustion chamber. It is about improvement.

[0002]

2. Description of the Related Art Conventionally, in a direct injection type engine mounted on an automobile or the like, a nozzle portion of an injector is inserted through a seal member into a mounting hole opened in a combustion chamber formed in a cylinder head. The fuel is atomized and supplied from the injector to the combustion chamber. Japanese Patent Application Laid-Open No. 2000-9000 has proposed a mounting structure for the injector. This mounting structure is shown in FIG.
It will be described based on.

The mounting hole 1 formed in the cylinder head 11
A nozzle portion 33 formed below a large-diameter portion (main body) 32 of the injector 31 is inserted into 1a, and is elastically supported by an annular seal member. The small-diameter portion 35 formed above the large-diameter portion 32 is provided with a tubular protrusion 36 and a tubular connecting portion 37, and both members are connected to a delivery pipe 39 supported by the cylinder head 11 via a support arm 38. Have been. The mounting hole 11a has an insertion hole 11b for inserting the nozzle portion 33 and an accommodation hole 11 for accommodating the large diameter portion 32.
c, and a predetermined gap is formed between the bottom surface 11d of the accommodation hole 11c and the lower surface of the large diameter portion 32.
Then, the entire injector 31 is elastically supported by the cylinder head 11, so that transmission of the injector driving sound to the engine body side is cut off, thereby improving the quietness of the engine.

[0004]

The above-mentioned annular seal member 3
In No. 4, the diameter of the outer peripheral surface of the seal member 34 is set to be larger by a predetermined length than the diameter of the inner peripheral surface of the insertion hole 11b in order to achieve a seal between the combustion chamber and the atmosphere side. For this reason, in the work of mounting the injector 31, when the nozzle portion 33 in which the annular seal member 34 is externally fitted is inserted into the insertion hole 11 b, the sliding between the inner peripheral surface of the insertion hole 11 b and the outer peripheral surface of the seal member 34 is performed. The dynamic resistance becomes large, so that the seal member 34 is shifted in the axial direction of the injector 31. Therefore, in the mounting structure described in the above publication, in order to position the seal member 34 in the axial direction of the injector 31, the seal member 34 is externally fitted into an annular groove 33a formed on the outer peripheral surface of the nozzle portion 33. Like that.

However, when the annular groove 33a is formed in the nozzle portion 33 as described above, there is a problem that the strength of the nozzle portion 33 is reduced because the nozzle portion 33 is thin. Further, it is conceivable to increase the thickness of the nozzle portion 33 in order to secure the required strength. However, in this case, another problem occurs in that the injector 31 becomes large. Further, when the seal member 34 is externally fitted in the annular groove 33a, the seal member 34 must be expanded to a size larger than the outer diameter of the nozzle portion 33 against its own elastic force. there were.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an injector mounting structure capable of positioning an annular seal member in an axial direction of an injector without reducing the strength or increasing the size of the injector.

[0007]

The means for achieving the above object and the effects thereof will be described below. In order to solve the above problem, according to the first aspect of the present invention, an injector is supported in a mounting hole formed in an engine body and opened to a combustion chamber via an annular seal member made of an elastic body. In the mounting structure of (1), the annular seal member is provided with a flange portion for preventing movement of the seal member in the axial direction of the injector.

According to the above configuration, the positioning of the annular seal member in the axial direction of the injector is performed by the flange portion. Therefore, it is not necessary to form an annular groove in the injector for positioning the annular seal member, and it is possible to avoid a decrease in strength and an increase in size of the injector due to the formation of the annular groove. Thus, the annular seal member can be positioned in the axial direction of the injector without reducing the strength or increasing the size of the injector.

According to a second aspect of the present invention, in the first aspect, the flange portion is sandwiched between the engine body and the injector from both axial sides of the injector.

According to the above configuration, since the flange portion is sandwiched between the engine body and the injector from both sides in the axial direction of the injector, the annular seal member is positioned in the axial direction of the injector. be able to.

According to the third aspect of the present invention, the first or second aspect is provided.
In the described invention, the injector is elastically supported by the flange portion. According to the above configuration, the transmission of vibration between the injector and the engine body can be suppressed by the flange portion of the annular seal member.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the annular seal member has a nozzle portion of the injector inserted therein.
The gist is that a tapered surface having a smaller diameter toward the tip is formed on an outer peripheral edge of an end of the annular seal member on the tip end side of the nozzle portion.

According to the above construction, when the nozzle portion is inserted into the mounting hole with the annular sealing member mounted on the nozzle portion, or when the annular sealing member is inserted into the mounting hole before mounting the annular sealing member on the nozzle portion. The insertion can be smoothly performed by the tapered surface formed on the outer edge of the distal end of the annular seal member.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the annular seal member has a nozzle portion of the injector inserted therein.
The gist is that a tapered surface having a smaller diameter toward the tip is formed on the inner peripheral edge of the end opposite to the tip of the annular seal member.

According to the above configuration, when the annular seal member is mounted on the nozzle portion, the mounting can be smoothly performed by the tapered surface formed on the inner peripheral edge of the end opposite to the distal end of the annular seal member.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an injector mounting structure in a direct injection engine will be described below with reference to FIGS.

FIG. 3 is a sectional view showing a structure for mounting the injector to the cylinder head of the engine. The cylinder head 11 shown in FIG. 3 covers each cylinder of a cylinder block (not shown), and a combustion chamber R is formed between the cylinder head 11 and a piston (not shown) accommodated in each cylinder. . Also, cylinder head 1
1 is provided with an injector 12. Here, FIG. 1 is an enlarged view of a portion of the cylinder head 11 where the injector 12 is mounted.

As shown in FIG. 1, the cylinder head 1
1, a mounting hole 11a is formed so as to communicate the combustion chamber R with the atmosphere, and an injector 12 is mounted in the mounting hole 11a. At the center of the lower end of the cylindrical main body 13 of the injector 12, a cylindrical mounting cylindrical portion 13a is provided.
Are integrally formed, and the nozzle portion 14 is attached to the mounting cylinder portion 13a.
Is detachably mounted. The nozzle portion 14 includes a cylindrical portion 14a and a large-diameter portion 14b formed on an outer peripheral portion of a base end thereof. An annular groove 14c is formed on the outer peripheral surface of the large diameter portion 14b, and a seal ring 15 is fitted into the annular groove 14c so as to seal the inner peripheral surface of the mounting cylinder 13a. The upper surface of the large diameter portion 14b and the main body 1
A washer 16 is interposed between the third central hole 13b and a step 13c formed in the center hole 13b. A fuel injection hole 14d is formed at the tip of the cylindrical portion 14a.

A fastening member 1 having a female thread 17a is provided on a male thread 13d formed on the outer peripheral surface of the mounting cylinder 13a.
7 is screwed into the nozzle portion 1 by the flange portion 17b.
4 together with the washer 16 is fastened and fixed to the step 13c side.

Mounting hole 11a of the cylinder head 11
A second insertion hole 11b into which the nozzle portion 14 is loosely inserted with a first gap G1 having a cylindrical shape, and a second end which is connected to one end of the insertion hole 11b and wherein the fastening member 17 has a cylindrical shape.
A first accommodation hole 11c accommodated with a gap G2. The bottom surface 11d of the first accommodation hole 11c is formed as a tapered surface whose diameter decreases toward the distal end of the injector 12.

In the first gap G1 between the outer peripheral surface of the cylindrical portion 14a of the nozzle portion 14 and the inner peripheral surface of the insertion hole 11b, a cylindrical portion 18a of an annular sealing member 18 made of, for example, resin is interposed. The seal at G1 is provided. Between the tapered bottom surface 11d and the lower surface of the flange portion 17b of the fastening member 17, a flange portion 18b formed integrally with the base end portion of the seal member 18 is interposed, and the axially downward pressing force acting on the injector 12 is exerted. Try to catch the pressure. The upper surface of the flange portion 18b in contact with the lower surface of the flange portion 17b is an annular flat surface 18c, and the lower surface in contact with the tapered bottom surface 11d is a tapered surface 18d having the same inclination angle as the tapered bottom surface 11d. . A tapered surface 18e having a smaller diameter toward the distal end is formed on the outer peripheral edge of the distal end of the cylindrical portion 18a, so that the distal end of the cylindrical portion 18a can be easily inserted into the insertion hole 11b of the engine body. The inner peripheral edge of the flange portion 18b is formed with a tapered surface 18f having a smaller diameter toward the tip of the injector 12, and the nozzle portion 14a is formed with respect to the cylindrical portion 18a of the seal member 18.
Is easy to insert.

In the single state before the sealing member 18 is assembled into the mounting hole 11a, the outer diameter D1 of the cylindrical portion 18a is the same as the inner diameter D2 of the insertion hole 11b as shown in FIG. It is set slightly larger as shown by. Also, as shown in FIG.
The inner diameter dimension D3 of the nozzle section 8a is set smaller than the outer diameter dimension D4 of the cylindrical section 14a of the nozzle section 14, so that a predetermined interference can be ensured in the assembled state to maintain the sealing performance.

Next, a pressing and holding mechanism for pressing and holding the main body 13 of the injector 12 at a predetermined position will be described. As shown in FIG. 1, pressed portions 13 e are integrally formed on the outer peripheral surface of the lower end of the main body 13 at two right and left portions.
The attachment hole 11a of the cylinder head 11 has a second accommodation hole 11e having a diameter larger than that of the accommodation hole 11c, and a bottom surface 11f of the second accommodation hole 11e is an annular flat surface. A cylindrical fourth gap G4 is formed between the outer peripheral surface of the pressed portion 13e and the inner peripheral surface of the second accommodation hole 11e, and the pressed portion 13e
A flat ring-shaped fifth gap G5 is formed between the lower surface of the first member 11 and the bottom surface 11f.

As shown in FIG. 3, a base end 21a of a pressing member 21 is supported on the upper surface 11g of the cylinder head 11, and a bifurcated pressing portion 21b provided at a distal end of the pressing member 21 is covered with the fork. It is in contact with the pressing portion 13e. The bolt insertion hole 2 formed in the center of the pressing member 21
1c to female thread 11h formed on cylinder head 11
The injector 12 is held at a predetermined position of the cylinder head 11 by screwing a bolt 22 to the cylinder head 11.

As shown in FIG. 3, a connection cylinder 23 is connected to the upper end of the main body 13, and a fuel supply pipe 24 is connected to the connection cylinder 23. A terminal block 25 is connected to the connection cylinder 23, and an ECU (not shown) is connected to the terminal block 25.
A connector 27 connected via a lead wire 26 is connected.

When assembling the injector 12 to the cylinder head 11, only the sealing member 18 is inserted into the insertion hole 11b of the cylinder head 11, and then the nozzle portion 14 of the injector 12 is connected to the cylindrical portion 18 of the sealing member 18.
There is a method of press-fitting inside a. In addition, nozzle part 1
4, a sealing member 18 may be fitted in advance, and the sealing member 18 may be press-fitted into the insertion hole 11b together with the nozzle portion 14. In the former case, the outer diameter D1 (seal member) and the inner diameter D2 (insertion hole) shown in FIG. 2A are made equal, and the outer diameter D4 (nozzle part) shown in FIG. (Seal member). In the latter case, the outer diameter D1 (seal member) is changed to the inner diameter D2.
(Insertion hole) and make the inner diameter D3 (seal member) and the outer diameter D4 (nozzle) equal. In any case, if the sealing performance is ensured by only one of the interferences, the assembling work becomes easy.

After the fitting operation of the injector 12 is completed, the pressing member 21 is set, and the pressing portion 21b of the pressing member 21 is pressed by the bolt 22 against the pressed portion 13e. In this state, the second accommodation hole 11e and the pressed portion 13
e, a cylindrical fourth gap G4, a flat ring-shaped fifth gap G5 between the bottom surface 11f and the pressed portion 13e, and the main body 13 and the nozzle portion 14 It will be elastically supported by the part 18b.

The injector 12 configured as described above
During the operation of the engine, the fuel is atomized into the combustion chamber R by an operation signal from an ECU (not shown) and is periodically injected and supplied. During operation, the pressure in the combustion chamber R fluctuates, but the seal between the outside air and the combustion chamber R is secured by the cylindrical portion 18a of the seal member 18, and the flange portion 18b elastically supports the injector 12 and Vibration transmission between the engine 12 and the engine is suppressed.

According to the mounting structure of the injector in the engine of the above embodiment, the following effects can be obtained. (1) In the above embodiment, the sealing member 18 is
a and a flange portion 18b, the cylindrical portion 18a is interposed in the first gap G1 between the outer peripheral surface of the cylindrical portion 14a of the nozzle portion 14 and the inner peripheral surface of the insertion hole 11b, and the flange portion 18b is fastened to the tapered bottom surface 11d. It was interposed in the third gap G3 between the attachment member 17 and the flange portion 17b. The flange portion 18b of the seal member 18 is sandwiched from both sides in the axial direction of the injector 12 by the tapered bottom surface 11d and the flange portion 17b of the fastening member 17, whereby the flange portion 18b is positioned in the axial direction. For this reason, the cylindrical portion 1 of the nozzle portion 14
It is not necessary to process the annular groove for positioning the above-mentioned axial direction by fitting a seal member into 4a, so that the injector 12 can be easily manufactured and cost can be reduced. Also, the cylindrical portion 14 of the nozzle portion 14
A reduction in the strength of the nozzle portion 14 due to the provision of the annular groove in a, and an increase in the wall thickness of the nozzle portion 14 for suppressing the reduction in strength can be avoided. Further, the sealing member 18
By simply inserting the cylindrical portion 14a of the nozzle portion 14 into the cylindrical portion 18a, the seal member 18 can be assembled, and this assembling workability can be improved.

(2) In the above embodiment, the sealing member 18
The injector 12 is elastically supported by the flange portion 18b, so that vibration transmitted from the fuel supply pipe 24 side to the injector 12 and vibration of the injector 12 itself during operation of the engine are reduced by the flange portion 18b of the seal member 18. As a result, the propagation of the vibration to the cylinder head 11 is suppressed. Further, the vibration of the engine is also reduced by the flange portion 18b, and the propagation of the vibration to the injector 12 is suppressed.

(3) In the above embodiment, the bottom surface of the housing hole 11c is a tapered bottom surface 11d and the sealing member 1
8 has a tapered surface 18e formed at the outer peripheral edge of the distal end of the cylindrical portion 18a.
b, the tapered bottom surface 11d and the tapered surface 1
8e guides the distal end of the cylindrical portion 18a toward the axis of the insertion hole 11b, so that this insertion operation can be performed smoothly.

(4) In the above embodiment, the flange 18
b, the tapered surface 18f is provided on the inner peripheral edge of the cylindrical portion 18b.
When the nozzle portion 14 is inserted into the cylindrical portion 18a, the nozzle portion 14 is guided by the tapered surface 18f toward the axis of the cylindrical portion 18a, so that the inserting operation can be easily performed.

(5) In the above embodiment, the bottom surface of the housing hole 11c is not only the tapered bottom surface 11d, but the tapered surface 18d is formed on the lower surface of the flange portion 18b of the seal member 18. Therefore, when the assembly of the injector 12 is completed, the flange portion 18b of the seal member 18 is prevented from being displaced in the lateral direction (radial direction) by the tapered bottom surface 11d, and the assembly state of the nozzle portion 14 and the seal member 18 is stabilized. Can be changed.

The above embodiment may be modified as follows. Other embodiments described below have a configuration in which the seal member 18 of the injector mounting structure in the engine of the above embodiment and members related thereto are changed, and therefore, detailed description of the same parts will be omitted.

FIG. 4 shows an example in which the bottom surface 11d of the accommodation hole 11c is in a horizontal state, and the flange portion 18b of the seal member 18 is in a flat state. In this example, since the shape is simplified, the molding die of the seal member 18 can be simplified, and the processing of the bottom surface 11d can be easily performed.

FIG. 5 shows the cylindrical portion 18a of the seal member 18.
Is interposed in the cylindrical second gap G2, and the flange portion 18
An example is shown in which the inner peripheral surface of b is brought into press contact with the cylindrical portion 14a of the nozzle portion 14.

FIG. 6 shows an example in which the cylindrical portion 18a is fitted in the second gap G2 between the outer peripheral surface of the fastening member 17 and the inner peripheral surface of the accommodation hole 11c, and the flange portion 18b is interposed in the fifth gap G5. Is shown. In this example, since the diameter of the seal member 18 is large, the main body 13 of the injector 12 can be stably and elastically supported.

In another example shown in FIG. 7, another cylindrical portion 18g interposed in the second gap G2 is provided on the flange portion 18b of the seal member 18, and the fifth portion is provided on the cylindrical portion 18g.
An example is shown in which another flange portion 18h interposed in the gap G5 is provided. In this example, the nozzle portion 14 and the main body 13 can be more stably elastically supported.

Next, technical ideas that can be grasped from the above embodiments are listed below. (1) In claim 1, the mounting hole is formed so as to communicate with an insertion hole for inserting the nozzle portion of the injector with a first cylindrical gap, and an end of the insertion hole on the outside air side, and the nozzle portion is formed as a main body. The annular seal member has a cylindrical portion interposed in the first gap, and the flange portion has An injector mounting structure interposed in a third gap between a bottom surface of the housing hole and a lower surface of the fastening member.

(2) In the first aspect, the mounting hole is formed so as to communicate with an insertion hole for inserting a nozzle portion of the injector with a first cylindrical gap, and an end of the insertion hole on the outside air side. A large-diameter first accommodation hole for accommodating a fastening member for connecting the portion to the main body with a cylindrical second gap;
A second housing hole formed to communicate with the outside air side end of the first housing hole, having a diameter larger than that of the first housing hole, and housing the lower end of the main body with a cylindrical fourth gap. The annular seal member includes a cylindrical portion interposed in the second gap, and the flange portion is interposed in a ring-shaped fifth gap between the bottom surface of the second housing hole and the lower surface of the main body. Mounting structure.

(3) In the above (2), the injector mounting structure in which the cylindrical portion is interposed in the second gap and the flange portion is interposed in the third gap. (4) In the above (2), the seal member is formed in a step shape by two cylindrical portions and two flange portions, and the two cylindrical portions are interposed in the first and third gaps, and the two flange portions are provided. Is a mounting structure of the injector interposed in the third and fifth gaps.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment embodying an injector mounting structure of the present invention.

2A is a cross-sectional view showing a state where a seal member is fitted into an insertion hole of a cylinder head, and FIG. 2B is a cross-sectional view showing a state where a nozzle portion is inserted into the seal member.

FIG. 3 is a vertical cross-sectional view showing an attached state of the injector.

FIG. 4 is a partial cross-sectional view showing another example embodying the present invention.

FIG. 5 is a partial cross-sectional view showing another example embodying the present invention.

FIG. 6 is a partial cross-sectional view showing another example embodying the present invention.

FIG. 7 is a partial sectional view showing another example embodying the present invention.

FIG. 8 is a longitudinal sectional view showing a state of attachment of a conventional injector.

[Explanation of symbols]

R: combustion chamber, G1: first gap, G2: second gap, third gap, G3: third gap, G4: fourth gap, G5: fifth gap, 11: cylinder head, 11a: mounting hole, 11b …
Insertion hole, 11c: first accommodation hole, 11d, 11f: bottom surface,
11e 2nd accommodation hole, 12 ... injector, 13 ... body, 14 ... nozzle part, 17 ... fastening member, 18 ... annular sealing member, 18a, 18g ... cylindrical part, 18b, 18h ... flange part, 18e, 18f ... Tapered surface, 21: pressing member, 22: bolt.

Claims (5)

[Claims] 1. An injector mounting structure in which an injector is supported in a mounting hole formed in an engine body and opened to a combustion chamber via an annular seal member made of an elastic body. An injector mounting structure, wherein a flange portion is provided for preventing the seal member from moving in the axial direction of the injector. 2. An injector mounting structure according to claim 1, wherein said flange portion is sandwiched between said engine body and said injector from both axial sides of said injector. 3. The mounting structure for an injector according to claim 1, wherein said injector is elastically supported by said flange portion. 4. The annular sealing member according to claim 1, wherein a nozzle portion of the injector is inserted into the annular sealing member, and an outer peripheral edge of an end of the annular sealing member on a tip end side of the nozzle portion. Has a tapered surface with a smaller diameter toward the tip. 5. The annular seal member according to claim 1, wherein a nozzle portion of the injector is inserted into the annular seal member, and the annular seal member is provided at an inner peripheral edge of an end opposite to a tip end of the annular seal member. Is a mounting structure for an injector having a tapered surface with a smaller diameter toward the tip.