JP4359012B2 - Engine negative pressure pump piping structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine negative pressure pump piping structure applied to, for example, a diesel engine.
[0002]
[Prior art]
Generally, since a diesel engine does not have a throttle valve, negative pressure is not generated. In an engine having a normal throttle valve, when the throttle valve is closed, for example, a negative pressure is generated at a site where combustion air passing through a filter is sucked. And this negative pressure is utilized as operating sources, such as a brake system, various control valves, and a supercharger (henceforth a turbocharger), for example.
[0003]
For this reason, the diesel engine is equipped with a negative pressure pump (hereinafter referred to as a vacuum pump), and this vacuum pump is driven in conjunction with the drive system of the engine to provide a brake system, various control valves, a turbocharger, etc. Is building a negative pressure pump system .
[0004]
By the way, as shown schematically in FIG. 5, such a negative pressure pump system generates a negative pressure generated from a vacuum pump 51 driven in conjunction with an engine drive system by using a rubber or resin tube 52 and It is directly supplied to the brake master power (M / P) connected through an installation pipe (metal pipe) 53. Further, the negative pressure from the vacuum pump 51 is temporarily supplied and accumulated in a vacuum tank 56 connected via a rubber or resin tube 54 and a T-shaped joint member 55 branched from the installation pipe 53. The negative pressure of the vacuum tank 56 is supplied to a turbocharger 61 connected downstream of the exhaust manifold assembly 60 via a rubber or resin tube 57, a control valve (EVRV) 58, and a vacuum damper 59. is doing. The negative pressure accumulated in the vacuum tank 56 is supplied to a swirl control valve (SWCV) 65 via a branch pipe (rubber or resin tube) 62 branched from the vacuum tank 56, a solenoid valve 63, and a vacuum damper 64. Is also configured to supply.
[0005]
In attaching a vacuum pump in a conventional diesel engine, a chain case is formed on one end face side of the cylinder block as disclosed in, for example, Japanese Patent Laid-Open No. 8-86222. A structure in which a pump shaft of a vacuum pump is faced in the chain case, and a winding transmission body such as a timing belt or a chain belt serving as a means for transmitting driving force from the crankshaft is hung around the pump shaft. Some have
[0006]
However, a negative pressure passage forming member (hereinafter referred to as a vacuum pipe) connected to the vacuum pump uses a long tube made of rubber or resin for most of the piping system of the negative pressure pump. Moreover, the current situation is that piping is provided in a portion having a large thermal influence such as around the lower part of the exhaust side of the engine block.
[0007]
[Problems to be solved by the invention]
For this reason, in the piping structure of the conventional vacuum pipe described above, the vacuum pipe is deteriorated due to thermal influence, and the durability is likely to be lowered. In addition, the piping around the lower part on the exhaust side of the engine block is troublesome for piping and replacement work. Also, coupled with piping and wiring work such as breather pipes and harnesses that are piped and wired in the upper part of the engine block, the number of parts for assembling them increases and the cost increases.
[0008]
Since a long tube made of rubber or resin is used as the vacuum pipe, it is necessary to use a clamp for positioning the piping work. In addition, such a tube is forcibly bent using the elasticity of the material at a piping place where the tube must be bent extremely. For this reason, the bending part of a tube deform | transforms easily and is crushed and the flow of a negative pressure flow worsens. Furthermore, when wiring harnesses or the like, an original clamp mounting stay must be attached to the engine block or the like in advance.
[0009]
The present invention has been made in view of the above circumstances, and provides an engine negative pressure pump piping structure capable of easily performing piping and wiring work in combination with improvement in durability of the vacuum pipe. With the goal.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an engine having a negative pressure pump, wherein at least a part of a negative pressure forming passage member connected to the negative pressure pump is formed by a metal pipe , A metal pipe is provided along the upper part of the head cover to be crowned by the upper cylinder head, and the metal pipe is fixed to the head cover so as to increase the rigidity of the head cover .
[0011]
By adopting such a configuration, a part of the negative pressure forming passage member connected to the negative pressure pump is arranged along the upper portion of the head cover to be crowned by the cylinder head. The piping of the members can be made compact and simple, and the workability can be improved. In addition, since the piping portion of the negative pressure forming passage member is on the head cover with relatively little thermal influence, there is little thermal influence on the negative pressure forming passage member as before, and durability can be improved.
[0013]
Further, by adopting such a configuration, since the metal pipe portion of the negative pressure forming passage member is piped along the upper portion of the head cover, the rigidity of the head cover is increased and it is advantageous against heat. .
[0014]
Furthermore, the present invention is characterized in that, in the above-described negative pressure pump piping structure of the engine, the upper surface of the head cover is formed to be uneven, and the metal pipe is supported by the convex portion of the upper surface of the head cover.
[0015]
With such a configuration, the piping work and mounting workability of the negative pressure forming passage member are improved, and the mounting surface of the head cover to which the negative pressure forming passage member is attached can be easily processed.
[0016]
Furthermore, the present invention provides the above described negative pressure pump piping structure for an engine, wherein the negative pressure forming passage member is fixed to the upper portion of the head cover via an attachment stay, and other piping or wirings are attached to the head cover via the attachment stay. It is characterized by having attached.
[0017]
By adopting such a configuration, it is possible to reduce the number of parts for assembly used for piping / wiring work of other piping or wiring, and the cost can be reduced.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings shown in FIGS. FIG. 1 is a front view of a horizontally placed in-line four-cylinder diesel engine installed in a front engine room of a vehicle as viewed from the driver's seat side. FIG. 2 is an enlarged perspective view of the main part of the internal structure of the chain case of the engine block. FIG. 3 is a plan view of the engine showing a vacuum pipe piping state of the vacuum pump. FIG. 4 is an explanatory view showing a state where the engine block is mounted in the engine room.
[0019]
As shown in FIGS. 1 and 2, in the basic form of the engine block 1 in the engine according to the present invention, the cylinder block 2 is formed of an upper block 3 and a lower block 4. The upper surface of the cylinder head 5 that forms the upper part of the cylinder block 2 is covered with a head cover 6. Further, a convex portion 6a composed of a plurality of chambers corresponding to each cylinder is formed on the upper surface of the head cover 6 so as to exhibit an uneven state. Furthermore, the lower part of the cylinder block 2 has a configuration in which an oil pan 7 is fastened and fixed.
[0020]
A crankcase (not shown) is formed between the upper block 3 and the lower block 4 in the cylinder block 2, and both ends of the crankshaft 8 are pivotally inserted into the crankcase. ing. A sprocket 9 is attached to the shaft support end side of the crankshaft 8, and this sprocket 9 faces the outside of the cylinder block 2, that is, a chain case 12 described later.
[0021]
Furthermore, a piston (not shown) is disposed inside the cylinder block 2 and the cylinder head 5. This piston is operated by an intake / exhaust valve that opens and closes by rotational driving of a camshaft 10 inserted into the upper part of the cylinder head 5, air supplied into the combustion chamber by the operation of the intake / exhaust valve, and supply to the combustion chamber The fuel is mixed and explodes when it explodes. Such a lifting and lowering operation of the piston is transmitted to the crankshaft 8 via a connecting rod (not shown) so that the crankshaft 8 is rotationally driven. Further, the driving force of the crankshaft 8 is transmitted by a timing chain 18 spanned between the sprocket 11 of the camshaft 10 and the sprocket 9 of the crankshaft 8 facing a chain case 12 described later. ing.
[0022]
The above-described chain case 12 is formed on the end face (one end face) opposite to the transmission side of the transmission T of the engine block 1 (see FIG. 4 described later). The chain case 12 has a structure in which a chain block 13 integrally formed on one end face of each of the cylinder block 2, the cylinder head 5, and the oil pan 7 having high rigidity and an outer open end face 13 a of the chain block 13 are closed. And a chain cover 14 that is removably assembled.
[0023]
A part of the chain block 13 constituting the chain case 12, that is, a part of the upper block 3 constituting the cylinder block 2 extends toward the exhaust side A as a side perpendicular to the crankshaft 8. In this way, the overhanging block portion 15 is formed.
[0024]
This overhanging block portion 15 is a mounting portion of a tensioner 17 that is installed on the exhaust A side of the engine block 1 together with the tension adjusting actuator 16 of the timing chain 18. The tensioner 17 is pivotally supported by the overhanging block 15 so as to be rotatable. Further, the sliding surface of the tensioner 17 is in contact with the slack side 18 </ b> A of the timing chain 18. As a result, a load is applied to the slack side 18A of the timing chain 18 so as to push the engine block 1 from the exhaust side A toward the intake side B from the outside to the inside. For this reason, the timing chain 18 maintains a tension state together with the tension side 18B, and thereby the tension on the slack side 18A of the timing chain 18 is adjusted.
[0025]
A vacuum pump 30 is provided in the overhanging block portion 15 formed integrally with the chain block 13 constituting the chain case 12 described above.
[0026]
As shown in FIG. 2, the vacuum pump 30 is arranged on the back side 15 a of the overhanging block portion 15, that is, the side facing the attachment side of the transmission T of the engine block 1 in the overhanging block portion 15. A sprocket 32 that is attached to the tip of the pump shaft 31 and spans the timing chain 18 is provided at the fitting end 30 a of the vacuum pump 30. Further, the fitting end 30 a of the vacuum pump 30 is fitted into a pump fitting opening 19 formed integrally and projecting in a cylindrical shape from the upper part of the back side 15 a of the overhanging block 15 toward the inside of the chain case 12. Next, the vacuum pump 30 is fastened by inserting a bolt 21 through a spring washer 22 into a bolt insertion hole 20 provided around the pump fitting opening 19. As a result, the vacuum pump 30 can be easily positioned without using a conventional knock pin or the like.
[0027]
Incidentally, a vacuum pipe 33 that forms a negative pressure forming passage is connected to the vacuum pump 30 attached to the back side 15 a of the overhanging block portion 15. The vacuum pipe 33 is connected to various auxiliary devices disposed on the outer wall and the upper surface of the engine block 1. As these auxiliary machines, for example, as shown in FIGS. 1, 2 and 3, an exhaust manifold 41 covered with a cover 41a connected to each cylinder, and a collective portion 41b of the exhaust manifold 41 are provided. There are a turbocharger 42 connected downstream, a catalytic converter 44 connected to the turbocharger 42 via a joint member 43, and the like, which are arranged on the outer wall 1a on the exhaust side A. In this case, since the cover 41 a of the exhaust manifold 41 is extended to a position facing the vacuum pump 30, the vacuum pump 30 is not easily affected by heat from the exhaust manifold 41.
[0028]
On the other hand, on the intake side B of the engine block 1, as shown in FIG. 3, an intake manifold 45, a swirl control valve (SWCV) 46, and the like are arranged. A vacuum pipe 33 connected to the vacuum pump 30 is provided on the head cover 6 that covers the cylinder head 5 on the upper surface of the engine block 1, and the end face on the trunk mission T side from the end face side on the chain case 12 side of the engine block 1. It is piped along. The vacuum pipe 33, the connecting end portion side of the vacuum pump 30 is formed by a resin pipe 34, the resin pipe 3 4 are connected to the metal pipe 35 sites that are piping along the top of the head cover 6 It is formed by.
[0029]
Further, a vacuum tank 39 for accumulating negative pressure and auxiliary equipments that are driven and controlled by using negative pressure as an operating source, such as a turbocharger 42, a swirl control valve (SWCV) 46, are provided on the terminal side of the metal pipe 35. The connecting pipe 36 and the branch pipes 36A, 36B and 36C connected to the brake master power (M / P) 49 and the like are respectively connected. And the connection end part a of the terminal part of the metal pipe 35 and the connection pipe 36 passes through the center part in the vehicle width direction when the engine block 1 is mounted in the engine room E / R, as shown in FIG. It is located on the central axis OO.
[0030]
Thus, the reason why the connection end a is provided in the center in the vehicle width direction is to facilitate the handling of negative pressure piping. Normally, a chain such as a chain case 12 and belts are wound around one end of the engine block 1 to drive the auxiliary machine, and a transmission M is directly coupled to the other end. Accordingly, when the engine is laid out horizontally in the engine room E / R, the engine block 1 is biased toward one side in the engine room E / R. For example, in the vehicle shown in FIG. 4, the engine block 1 is biased to the right side opposite to the driver's seat. In this case, the vacuum pump 30 is located toward the right end of the engine room E / R where the timing chain 18 is located.
[0031]
By the way, although the vehicle of FIG. 4 shows the case of the left steering wheel, the master power for braking (M / P) 49 needs to be located on the same side as the driver's seat. That is, in the vehicle of FIG. 4, the brake master power (M / P) is located on the left side, but in the case of a right-hand drive vehicle, it needs to be located on the right side of the vehicle. Therefore, it can be said that the connection end portion a is preferably located near the center of the vehicle in order to support both the right-hand drive vehicle and the left-hand drive vehicle.
[0032]
Further, since the brake master power (M / P) 49 and the swirl control valve (SWCV) 46 are arranged at the upper part of the engine room E / R, the brake master power (M / P) 49 and the swirl control valve (SWCV) 46 are arranged along the head cover 6 as in the present embodiment. By piping a negative pressure system and allowing branching of the negative pressure pipe at the upper center of the engine room, the piping can be improved.
[0033]
Further, the metal pipe 35 is attached to a convex portion 6a formed on the head cover 6 via an attachment stay 37, and a breather pipe 47 for blow-by gas passages is provided on the head cover 6. And other piping or wiring such as an electrical harness 48 are piped or wired. The breather pipe 47, the harness 48, and the like are bundled together on the metal pipe 35 of the vacuum pipe 33 with a clip 38 and attached together on the head cover 6 via an attachment stay 37 for fixing the metal pipe 35. It has been. Thereby, it becomes possible to reduce the number of parts for assembly used for piping or wiring work of other piping or wiring, and cost can be reduced.
[0034]
In other words, according to the above-described piping structure of the vacuum pump according to the present invention, the head cover 6 in which the metal pipe 35 of the vacuum pipe 33 connected to the vacuum pump 30 is crowned by the cylinder head 5 above the engine block 1. Piping along the top of the. Thereby, the piping of the vacuum pipe 33 can be performed compactly and easily, and workability can be improved. In addition, since the piping portion of the vacuum pipe 33 is on the head cover 6 with relatively little thermal influence, there is little thermal influence as before, and durability can be improved.
[0035]
In the above-described embodiment, the diesel engine has been described as an example, but the present invention can also be applied to a normal engine. In addition, it goes without saying that the present invention can be implemented with various modifications without departing from the gist of the present invention.
[0036]
【The invention's effect】
As described above, the engine negative pressure pump piping structure according to the present invention has the following excellent effects.
[0037]
According to the present invention, in an engine including a negative pressure pump, at least a part of a negative pressure forming passage member connected to the negative pressure pump is placed along an upper portion of a head cover that is covered by a cylinder head at the upper portion of the engine block. Since piping and the metal pipe are used as the head cover, piping of the negative pressure forming passage member can be performed in a compact and simple manner, thereby improving workability. In addition, since the piping portion of the negative pressure forming passage member is on the head cover with relatively little thermal influence, there is little thermal influence on the negative pressure forming passage member as before, and durability can be improved. .
[0038]
In the present invention, at least a part of the negative pressure forming passage member is formed of a metal pipe, and the metal pipe is piped along the top of the head cover, and the metal pipe is fixed to the head cover. The rigidity of the head cover can be increased, and it is advantageous for heat.
[0039]
Furthermore, since the metal pipe is supported by the convex portion on the upper surface of the head cover, the pipe work and mounting workability of the negative pressure forming passage member can be improved. The mounting surface of the head cover to be mounted can be easily processed.
[0040]
Furthermore, in the present invention, the negative pressure forming passage member is fixed to the upper portion of the head cover via an attachment stay, and other piping or wiring is attached to the head cover via the attachment stay. It is possible to reduce the number of parts for assembly used for wiring and wiring work of wiring, and to reduce the cost.
[Brief description of the drawings]
FIG. 1 is a front view of an engine block of an engine according to the present invention as viewed from the driver's seat side in front of a vehicle.
FIG. 2 is an enlarged perspective view of an essential part showing an internal configuration of a chain case of an engine block.
FIG. 3 is a plan view of an engine block showing a vacuum pipe piping state of the vacuum pump.
FIG. 4 is an explanatory diagram showing a mounting state of an engine block in an engine room.
FIG. 5 is a schematic explanatory diagram of a conventional general negative pressure pump system .

Claims (3)

In an engine with a negative pressure pump,
At least a part of the negative pressure forming passage member connected to the negative pressure pump is formed with a metal pipe, and the metal pipe is placed along an upper portion of a head cover to be crowned by a cylinder head at the upper portion of the engine block. A negative pressure pump piping structure for an engine, wherein the metal pipe is fixed to the head cover so that the rigidity of the head cover is increased by piping.   2. The negative pressure pump piping structure for an engine according to claim 1, wherein an upper surface of the head cover is formed to be uneven, and the metal pipe is supported by a convex portion of the upper surface of the head cover.   The engine according to claim 1 or 2, wherein the negative pressure forming passage member is fixed to an upper portion of the head cover, and other piping or wiring is attached to the head cover via an attachment stay. Negative pressure pump piping structure.

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