JP3692251B2 - Engine with fuel injection nozzle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine in which a fuel injection nozzle is disposed in a head cover.
[0002]
[Prior art]
The engine is configured as follows, for example.
That is, as shown in FIG. 8, a high-pressure fuel pipe (19) is provided in the head cover (5) so as to face the high-pressure fuel receiving portion (14) of the fuel injection nozzle (13) and connected to the fuel injection pump. The connector (80) at the tip of 12) is inserted into the head cover (5) from the through hole (19) and screwed into the high-pressure fuel receiving part (14). Further, in order to hermetically seal between the through hole (19) and the high pressure fuel receiving portion (14), the inner peripheral surface of the through hole (19) and the outer peripheral surface of the high pressure fuel receiving portion (14) A seal member (81) is provided between them.
The fuel pressurized by the fuel injection pump is pumped to the fuel injection nozzle (13) via the high-pressure fuel pipe (12), and is injected from the fuel injection nozzle (13) into the combustion chamber.
[0003]
[Problems to be solved by the invention]
In the fuel injection type engine, when performing maintenance of the valve operating device in the head cover (5), the high pressure fuel pipe (12) is removed from the high pressure fuel receiving part (14), and then the head cover (5). Will be removed from the cylinder head.
However, since the seal member (81) extends to the outer peripheral surface of the high-pressure fuel receiving part (14) in the head cover (5) in a state of being fitted into the through hole (19), During removal, the seal member (81) is caught by the high-pressure fuel receiving portion (14). For this reason, the seal member (81) has to be removed from the through hole (19), and accordingly, it takes time and effort to attach and detach the head cover (5).
[0004]
An object of the present invention is to provide an engine provided with a fuel injection nozzle that can reduce the trouble in attaching and detaching the head cover while maintaining the airtightness of the head cover. Another object of the present invention is to enable the high pressure fuel receiving portion of the fuel injection nozzle to be set at an appropriate position with respect to the through hole of the head cover so that the sealing action of the seal member can be reliably obtained.
[0005]
[Means for Solving the Problems]
[Invention of Claim 1]
In order to achieve the above object, the invention of claim 1 is configured as follows, for example, as shown in FIGS.
The fuel injection nozzle (13) is disposed in the head cover (5), the head cover (5) is provided with a through hole (19), and the through hole (19) is protruded from the fuel injection nozzle (13). The connector (20) provided at the tip of the high pressure fuel pipe (12) is inserted into the head cover (5) through the through hole (19) so as to face the (14), and the connector (20) is inserted into the high pressure fuel receiving portion. In an engine equipped with a fuel injection nozzle externally fitted and fixed to (14),
[0006]
A cover-side seal member (21) that seals between the inner peripheral surface of the through hole (19) and the outer peripheral surface of the connector (20) in an airtight manner is provided, and a fuel injection nozzle ( The tip portion (21a) on the 13) side is configured to be located closer to the head cover (5) side than the tip of the high pressure fuel receiving portion (14), and the inner peripheral surface of the connector (20) and the high pressure fuel receiving portion (14 ) Is provided with an injector-side seal member (22) that hermetically seals between the outer peripheral surface and the fulcrum portion (51) , the force point portion (53) , the action point , for example, as shown in FIGS. By providing a nozzle pressing tool (48) having a lever (46) provided with a portion (52) and a holding bolt (47), and providing a stopper (49) for receiving the lever (46), a holding bolt (47) The force injection point (53) of the insulator (46) is pressed by the pressing part (54) provided on the fuel injection nozzle at the action point (52) of the insulator (46) that swings around the fulcrum part (51). (13) is inserted into the nozzle insertion hole (3 3) When pushed in, the lever (46) swinging around the fulcrum (51) is received by the stopper (49). The pushing force of the nozzle (13) is prevented from becoming too strong.
[0008]
[Invention of Claim 2 ]
The invention of claim 2 is the configuration of the invention described in claim 1, which is constituted further as follows.
The stopper (49) is configured to receive the force point portion (53) of the insulator (46).
[0009]
[Invention of claim 3 ]
According to a third aspect of the present invention, in the structure of the first or second aspect of the present invention, the following structure is further provided.
The fuel injection nozzle (13) is pressed by the action point portion (52) while the fuel injection nozzle (13) is prevented from rotating by the action point portion (52) of the insulator (46).
[0010]
[Action and effect of the invention]
[Claim 1]
The invention of claim 1 has the following actions and effects.
Insert the tip of the high-pressure fuel pipe (12) into the head cover (5) through the through hole (19), and connect the connector (20) at the tip of the high-pressure fuel pipe (12) to the fuel injection nozzle (13). By being externally fitted and fixed to the portion (14), fuel can be injected from the fuel injection nozzle (13) into the cylinder (30).
[0011]
When the connector (20) is inserted into the head cover (5), the cover-side seal member (21) is located between the inner peripheral surface of the through hole (19) and the outer peripheral surface of the connector (20). Sealing in an airtight manner prevents oil mist scattered in the head cover (5) from leaking out of the head cover (5) through the through hole (19). In addition, the oil mist in the head cover (5) leaks out of the head cover (5) through the gap between the connector (20) and the high-pressure fuel receiving part (14) by the injector-side seal member (22). Is prevented. This reliably prevents the oil mist scattered in the head cover (5) from leaking out of the head cover (5). Further, the injector side seal member (22) prevents the fuel from leaking into the head cover (5) through the gap between the connector (20) and the high pressure fuel receiving portion (14).
[0012]
The cover side seal member (21) has such a configuration that the front end portion (21a) on the fuel injection nozzle (13) side is closer to the head cover (5) side than the front end of the high pressure fuel receiving portion (14). Because of this position, the cover side can be removed when the head cover (5) is attached / detached without removing the cover side seal member (21) from the through hole (19) prior to the attachment / detachment of the head cover (5) during maintenance. The seal member (21) is not caught by the high-pressure fuel receiving part (14). That is, the time and effort required for attaching and detaching the head cover (5) is reduced to the extent that it is not necessary to remove the cover side seal member (21) from the through hole (19) when the head cover (5) is attached and detached.
[0013]
The invention of claim 1 further exhibits the following actions and effects.
The movement of the lever (46) due to the tightening of the holding bolt (47) is stopped when the lever (46) is received by the stopper (49). Therefore, if the dimensional accuracy of the fuel injection nozzle (13), insulator (46), and stopper (49) is secured to some extent, the pushing force of the fuel injection nozzle (13) will be reduced during the tightening operation of the holding bolt (47). It is prevented from becoming too strong, and deformation of the fuel injection nozzle (13) caused by the pushing force can be prevented.
[0014]
Then, the high pressure fuel receiving portion (14) of the fuel injection nozzle (13) is accurately positioned with respect to the through hole (19) by the amount that the fuel injection nozzle (13) is not deformed by the tightening operation of the holding bolt (47). It can be made to oppose in position. This prevents the connector (20) fixed to the high-pressure fuel receiving part (14) from being displaced from an appropriate position with respect to the through hole (19) and reducing the sealing action of the cover side seal member (21). it can.
[0015]
[Claim 2 ]
The invention of claim 2 has the following actions and effects in addition to the actions and effects of the invention of claim 1 .
The stopper (49) can prevent the insulator (46) from being distorted by receiving the parts other than the force point (53) of the insulator (46), and the insulator (46) to the fuel injection nozzle (13) can be prevented accordingly. The pushing force can be made appropriate. Therefore, the fuel injection nozzle (13) can be reliably prevented from being deformed due to the tightening operation of the holding bolt (47), and the high pressure fuel receiving portion (14) of the fuel injection nozzle (13) can be connected to the through hole (19). It can be made to oppose in a more exact position. This can reduce the displacement of the connector (20) from the proper position with respect to the through hole (19), and can reliably ensure the sealing action of the cover side seal member (21).
[0016]
[Claim 3 ]
The invention of claim 3 has the following actions and effects in addition to the actions and effects of the invention of claim 1 or 2 .
By blocking the fuel injection nozzle (13) by the action point (52) of the insulator (46), the high-pressure fuel receiving part (14) of the fuel injection nozzle (13) is more accurately located with respect to the through hole (19). Therefore, it is possible to reduce the displacement of the connector (20) from the proper position with respect to the through hole (19) in the lateral direction, and the sealing action of the cover side seal member (21) can be reduced. It can be secured more reliably.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a fuel injection engine according to the present invention will be described below with reference to FIGS.
1 is a longitudinal sectional view showing a main part of a cylinder head portion of the fuel injection type engine, FIG. 2 is an enlarged view of a portion II in FIG. 1, and FIG. 3 is a schematic configuration diagram showing a fuel supply system of the fuel injection type engine. It is. 4A is a cross-sectional view taken along the line AA in FIG. 1, FIG. 4B is a cross-sectional view taken along the line BB in FIG. 1, and FIG. 4C is a cross-sectional view taken along the line C- in FIG. A sectional view taken along line C, and FIG. 4D is a sectional view taken along line DD in FIG. FIG. 5 is a plan view showing a main part with the head cover applied to the engine removed, and FIG. 6 is a schematic diagram for explaining the glow plug and the direction of the fuel injection axis applied to the engine.
[0018]
A cylinder head (3) is assembled to the upper side of the cylinder block (2) of the engine (1), and a piston (31) can be moved up and down in the cylinder (30) in the cylinder block (2). It is fitted. A cavity (32) is formed on the top surface of the piston (31).
A head cover (5) is attached to the upper side of the cylinder head (3), and a valve operating device (4), intake / exhaust valves (26) and (27) [see FIG. 5] and fuel injection are provided in the head cover (5). A nozzle (13) is arranged. The tip of the fuel injection nozzle (13) is inserted into the cylinder (30) with the fuel injection nozzle (13) inserted into the nozzle insertion hole (33) provided in the cylinder head (3). . In this embodiment, a three-cylinder fuel injection type engine is illustrated, and fuel injection nozzles (13a), (13b), and (13c) are arranged for each cylinder [see FIG. 3].
[0019]
Further, the cylinder head (3) is provided with a plug insertion hole (34), and a glow plug (35) is screwed into the plug insertion hole (34) and the tip of the glow plug (35) is inserted. Is rushed into the cylinder (30). The fuel injection nozzle (13) is set in a direction parallel to the cylinder center axis (44), and the glow plug (35) is inclined with respect to the cylinder center axis (44) [FIG. reference].
[0020]
A high-pressure fuel receiving part (14) is projected on the side surface of the fuel injection nozzle (13), and one end side of the high-pressure fuel pipe (12) is connected to the high-pressure fuel receiving part (14). . As shown in FIG. 3, a fuel injection pump (8) is connected to the other end of the high-pressure fuel pipe (12), and the fuel injection pump (8) and the fuel tank (6) are supplied with fuel. It communicates with the road (7). The fuel supply path (7) is provided with a fuel filter (9), a feed pump (10) and an auxiliary filter (11) in order from the fuel tank (6) side.
The head cover (5) is provided with a through hole (19), and the through hole (19) is opposed to the high pressure fuel receiving portion (14) of the fuel injection nozzle (13). Then, the connection tool (20) attached to the tip of the high-pressure fuel pipe (12) is inserted into the head cover (5) from the through hole (19), and the connection tool (20) is inserted into the high-pressure fuel receiving part. It is screwed to (14) [see FIG. 2].
[0021]
The fuel in the fuel tank (6) is filtered by the fuel filter (9) and the auxiliary filter (11) to remove dust in the fuel, and then the fuel injection pump (8) by the feed pump (10). ). The fuel is pumped to the fuel injection nozzle (13) through the high-pressure fuel pipe (12) while being pressurized by the fuel injection pump (8), and the fuel injection nozzle (13) is directed into the combustion chamber. Be injected.
[0022]
Between the through hole (19) and the connector (20) and between the connector (20) and the high-pressure fuel receiving part (14), as shown in FIG. It is sealed.
That is, a cover-side seal member (21) is provided between the inner peripheral surface of the through hole (19) and the outer peripheral surface of the connector (20), and the fuel injection of the cover-side seal member (21) The tip (21a) on the nozzle (13) side is configured to be positioned closer to the head cover (5) than the tip of the high-pressure fuel receiving part (14).
The cover-side seal member (21) includes a through-hole side sealing portion (21b) that is in pressure contact with the inner peripheral surface of the through-hole (19), and a connector-side seal that is in pressure contact with the outer peripheral surface of the connector (20). And an elastic part (21d) that can be elastically deformed between the through hole side sealing part (21b) and the connector side sealing part (21c). I'm allowed. The cover-side seal member (21) is retained by a core material (21e).
[0023]
An injector-side seal member (22) is provided between the inner peripheral surface of the connector (20) and the outer peripheral surface of the high-pressure fuel receiving portion (14). That is, a groove (23) is provided around the outer peripheral surface of the high-pressure fuel receiving portion (14), and the injector-side seal member (22) is disposed in the groove (23). For example, as shown in FIG. 7, the injector-side seal member (22) may be disposed in a groove (24) provided around the inner peripheral surface of the connector (20).
[0024]
The cover-side seal member (21) prevents oil mist scattered in the head cover (5) from leaking out of the head cover (5) through the through hole (19). Also, by the injector-side seal member (22), oil mist scattered in the head cover (5) passes through the gap between the connector (20) and the high-pressure fuel receiving part (14) and is outside the head cover (5). And the fuel is prevented from leaking into the head cover (5) through the gap between the connector (20) and the high-pressure fuel receiving part (14).
An overflow fuel outlet (15) is formed at the upper end of each fuel injection nozzle (13), and the overflow fuel outlet (15) has an overflow fuel return path (18) as shown in FIG. ) Through the fuel tank (6). Further, the fuel injection pump (8) and each fuel injection nozzle (13a) (13b) (13c) are communicated with each other through an overflow fuel passage (16) (17).
[0025]
Next, the detailed configuration of the valve gear (4) will be described.
That is, the rocker arm bracket (37) is placed on the cylinder head (3), and the fixing bolt (38) is inserted into the cylinder head with the fixing bolt (38) passing through the rocker arm bracket (37). Screwed onto (3). The rocker arm bracket (37) is fixed to the cylinder head (3) by pressing the rocker arm bracket (37) with the bolt head of the fixing bolt (38).
[0026]
The rocker arm bracket (37) is fixed in a state of penetrating the rocker arm pivot (39), and the rocker arm (40) is swingably attached to the rocker arm pivot (39). The input part (40a) of the rocker arm (40) is brought into contact with a push rod (41) interlocked with a valve cam (not shown), and the output part (40b) of the rocker arm (40) is connected to a valve bridge (42). [See Fig. 5]. The intake / exhaust valves (26) and (27) are opened and closed by the valve cam through the push rod (41) and the rocker arm (40) in this order.
As shown in FIG. 5, a pair of intake valves (26) (26) and a pair of exhaust valves (27) (27) are arranged for each cylinder, and the pair of intake valves (26) (26) ) One valve bridge (42) is installed between the valve shaft heads, and one valve bridge (42) is installed between the valve shaft heads of the pair of exhaust valves (27) and (27). It is.
[0027]
The fuel injection nozzle (13) is pushed into the nozzle insertion hole (33) by the following configuration and fixed to the cylinder head (3).
That is, a nozzle pressing tool (48) having a lever (46) and a pressing bolt (47) is provided on the rocker arm bracket (37). The insulator (46) is formed in a plate shape, with one end (right side in FIG. 1) having a fulcrum part (51) and the other end (left side in FIG. 1) having an action point part (52). A power point portion (53) is formed in the middle portion. The lower end of the holding bolt (47) is screwed to the cylinder head (3), and the nut (54) is screwed to the upper end of the holding bolt (47).
[0028]
As shown in FIG. 4D, the rocker arm bracket (37) is provided with a locking groove (50), and a part of the circumferential surface of the holding bolt (47) is provided in the locking groove (50). The rocker arm bracket (37) is prevented from rotating by the holding bolt (47) and the fixing bolt (38). In other words, the retainer bolt (47) strengthens the locking of the rocker arm bracket (37), and this prevents the intake / exhaust valves (26) and (27) from being misaligned, thereby ensuring proper intake and exhaust timing. It can be set accurately and good combustion can be realized.
[0029]
Further, a stopper (49) is provided on the top of the rocker arm bracket (37) as shown in FIGS. The stopper (49) extends from the end of the rocker arm bracket (37) on the fuel injection nozzle (13) side [left side in FIG. 4 (A)] to both sides of the holding bolt (47) [left and right in FIG. 4 (C)]. It is set up along both sides], and the stopper (49) receives the force point portion (53) of the insulator (46).
On the other hand, pressure receiving surfaces (58) and (58) are provided at both side positions (left and right positions in FIG. 4B) of the shaft portion (28) of the fuel injection nozzle (13), and the pressure receiving surfaces (58) ( 58) is in contact with the action point (52) of the insulator (46).
[0030]
Then, the force point portion (53) of the lever (46) is pressed by the fastening force of the nut (54) with respect to the holding bolt (47), so that fuel is applied at the action point portion (52) of the lever (46). The pressure receiving surfaces (58) and (58) of the injection nozzle (13) are pressed, whereby the fuel injection nozzle (13) is pushed into the nozzle insertion hole (33). Further, as shown in FIG. 1, the action point portion (52) is formed in a circular arc surface convex toward the pressure receiving surface (58), and the pressure receiving force is raised and lowered by the elevation of the action point portion (52). The pressure receiving point of the surface (58) is prevented from shifting. The fuel injection nozzle (13) is received through the copper packing (61) at the inner end of the nozzle insertion hole (33).
[0031]
Further, a long hole (60) is provided on the side of the point of action (52) of the insulator (46) (left side in FIG. 4A), and the fuel injection nozzle (60) is provided in the long hole (60). The flat shaft portion (28) of 13) is inserted. The fuel injection nozzle (13) is prevented from rotating by the fitting of the elongated hole (60) and the shaft portion (28), and is viewed in a direction parallel to the cylinder center axis (44) as shown in FIG. Thus, it is possible to reliably maintain a state in which the pair of fuel injection axes (70) and (70) adjacent to the fuel injection nozzle (13) pass through both sides of the glow plug (35). As a result, the direct hit of the injected fuel to the glow plug (35) is less likely to occur, and burning of the glow plug (35) due to this can be suppressed. Instead of providing the elongated hole (60), the action point portion (52) side of the insulator (46) is formed in, for example, a bifurcated shape, and between the bifurcated action point portion (52) side. The shaft part (28) of the fuel injection nozzle (13) may be fitted to stop the fuel injection nozzle (13) from rotating.
[0032]
The nozzle pressing tool (48) has the following functions in addition to the function of fixing the fuel injection nozzle (13) to the cylinder head (3).
That is, the fulcrum part (51) of the insulator (46) is placed on and contacted with the upper end part of the rocker arm bracket (37), and the rocker arm bracket (37) is pressed by the fulcrum part (51). Further, a knock pin (63) is fixed to the upper end portion of the rocker arm bracket (37), and the knock pin (63) is fitted into a fitting hole (64) provided on the fulcrum portion (51) side of the lever (46). ), The fulcrum (51) side of the insulator (46) is prevented from rotating, so that the attitude of the insulator (46) does not shift. Then, by pressing the rocker arm bracket (37) at the fulcrum part (51), the rocker arm bracket (37) is lifted when the rocker arm (40) is operated, and the opening / closing timing of the intake / exhaust valves (26) (27) is incorrect. Therefore, it is possible to accurately set the proper intake / exhaust timing, and to realize good combustion.
The insulator (46) is set in a direction perpendicular to the fuel injection nozzle (13) above the fixing bolt (38). A lubricating oil passage (69) to the rocker arm (40) is provided from the cylinder head (3) to the rocker arm bracket (37).
[0033]
And the pressing force of the rocker arm bracket (37) by the fixing bolt (38) and the pressing force of the rocker arm bracket (37) by the nut (54) applied via the lever (46) are the above-mentioned rocker arm pivot (39). Acts on mutually opposite locations (67) and (68) [left and right locations in FIG. 1] of the rocker arm bracket (37). That is, the rocker arm bracket (37) is firmly attached to the cylinder head (3) by the pressing force of the rocker arm bracket (37) by the fixing bolt (38) and the nut (54). Thereby, it is possible to prevent the lubricating oil flowing through the lubricating oil passage (69) from leaking from the boundary between the cylinder head (3) and the rocker arm bracket (37). In addition, the floating of the mutually opposite locations (67) (68) during the operation of the rocker arm (40) is suppressed, and fluctuations in the opening / closing timing of the intake / exhaust valves (26) (27) due to this are suppressed, so Exhaust timing can be set accurately and good combustion can be realized.
[0034]
In the above embodiment, a three-cylinder engine has been described as an example. However, the present invention can be applied to a single-cylinder engine, or can be applied to a two-cylinder engine or a multi-cylinder engine having four or more cylinders. it can.
[Brief description of the drawings]
FIG. 1 shows an embodiment of an engine provided with a fuel injection nozzle according to the present invention, and is a longitudinal sectional view showing a main part of a cylinder head portion of the engine.
FIG. 2 is an enlarged view of a portion II in FIG.
FIG. 3 is a schematic configuration diagram showing a fuel supply system of the engine.
4A is a cross-sectional view taken along line AA in FIG. 1, FIG. 4B is a cross-sectional view taken along line BB in FIG. 1, and FIG. 4C is FIG. FIG. 4D is a cross-sectional view taken along line D-D in FIG. 1.
FIG. 5 is a plan view showing the main part with the head cover applied to the engine removed.
FIG. 6 is a schematic diagram illustrating a glow plug and a fuel injection axis direction according to the engine.
FIG. 7 is a longitudinal sectional view of a main part showing another embodiment of an engine provided with a fuel injection nozzle according to the present invention.
FIG. 8 is a view corresponding to FIG. 2 showing an engine equipped with a conventional fuel injection nozzle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 5 ... Head cover, 12 ... High pressure fuel pipe, 13 ... Fuel injection nozzle, 14 ... High pressure fuel receiving part, 19 ... Through-hole, 20 ... Connector, 21 ... Cover side sealing member, 21a ... The tip part of a cover side sealing member, 22 ... Injector-side seal member, 33 ... Nozzle insertion hole, 46 ... Insulator, 47 ... Presser bolt, 48 ... Nozzle presser, 49 ... Stopper, 52 ... Effect point of insulator, 53 ... Power point of insulator, 54 ... Nut [pressing part].

Claims (3)

The fuel injection nozzle (13) is disposed in the head cover (5), the head cover (5) is provided with a through hole (19), and the through hole (19) is protruded from the fuel injection nozzle (13). Facing the fuel receiving part (14),
A connecting tool (20) provided at the tip of the high-pressure fuel pipe (12) is inserted into the head cover (5) from the through hole (19), and the connecting tool (20) is inserted into the high-pressure fuel receiving section (14). In an engine equipped with a fuel injection nozzle fitted and fixed to
Provided is a cover-side seal member (21) that hermetically seals between the inner peripheral surface of the through-hole (19) and the outer peripheral surface of the connector (20), the cover-side seal member (21) of the above A tip part (21a) on the fuel injection nozzle (13) side is located closer to the head cover (5) side than the tip of the high-pressure fuel receiving part (14);
An injector-side seal member (22) that seals the inner peripheral surface of the connector (20) and the outer peripheral surface of the high-pressure fuel receiving portion (14) in an airtight manner;
A nozzle pressing tool (48) having a lever (46) having a fulcrum part (51) , a force point part (53) , and an action point part (52 ) and a holding bolt (47) is provided, and the lever (46) is received. By providing a stopper (49),
The point of action of the lever (46) that swings around the fulcrum (51) by pressing the force point (53) of the lever (46) with the pressing portion (54) provided on the holding bolt (47) When the fuel injection nozzle (13) is pushed into the nozzle insertion hole (33) provided in the cylinder head (3) in (52) , the lever (46) swinging around the fulcrum (51 ) is formed. It is configured to be received by the stopper (49), so that the pressing force of the fuel injection nozzle (13) is prevented from becoming too strong during the tightening operation of the holding bolt (47). An engine equipped with a fuel injection nozzle. An engine comprising the fuel injection nozzle according to claim 1 .
The stopper (49) is configured to receive the force point (53) of the insulator (46).
An engine equipped with a fuel injection nozzle. In the engine provided with the fuel injection nozzle according to claim 1 or 2 ,
The fuel injection nozzle (13) is configured to press the fuel injection nozzle (13) at the action point portion (52) in a state where the fuel injection nozzle (13) is prevented from rotating by the action point portion (52) of the lever (46).
An engine equipped with a fuel injection nozzle.

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