JPH0738652U - Exhaust gas recirculation device - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent heat damage to the EGR valve and to construct it at low cost. In an exhaust gas recirculation device configured to supply a part of exhaust gas into an intake manifold 5 via an EGR valve 6, a cylinder head 3 or an intake manifold located at one end of an engine room 1 in a vehicle width direction. EGR valve 6 can be directly attached to the EGR part and EGR can be performed with a simple structure.
The valve 6 was cooled by the running wind B.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an exhaust gas recirculation (EGR) device that reduces NO x in exhaust gas by recirculating a part of the exhaust gas to the intake system, and particularly to an EGR valve that controls the recirculation amount of the exhaust gas. The present invention relates to the improvement of the arrangement configuration.

[0002]

[Prior art]

 Conventionally, as disclosed in, for example, Japanese Utility Model Laid-Open No. 59-115846 and Japanese Utility Model Laid-Open No. 63-143754, a cylinder head integrally formed with a return passage for EGR gas is known. In addition, in the above-mentioned Japanese Utility Model Publication No. 59-115846, the intake manifold is further provided with a first recirculation passage communicating with the EGR gas recirculation passage of the cylinder head and a second recirculation passage communicating with the intake passage. An exhaust gas recirculation device is disclosed in which first and second recirculation passages are connected to each other and an EGR valve for controlling the EGR gas amount is directly attached.

[0003]

[Problems to be solved by the device]

 By the way, as described above, the passage for returning the EGR gas to the intake passage is formed in the cylinder head and the intake manifold, and the EGR valve is directly attached to the intake manifold, so that the external piping for the EGR gas and the EGR valve attachment means are provided. However, in the case of a horizontal engine as shown in Fig. 7, an EGR valve is arranged at the rear of the engine body in the vehicle traveling direction, which is disadvantageous to heat damage. There's a problem.

Explaining in detail with reference to FIG. 7, the engine body 22 is mounted horizontally in the engine room 21, and the intake manifold 23 is arranged on the rear side of the engine body 22 with respect to the vehicle traveling direction (direction A). Since the EGR valve 24 is attached to the intake manifold 23, the traveling wind B from the front of the vehicle is blocked by the engine body 22 and does not contribute to the cooling of the EGR valve 24. In particular, in recent years, the amount of EGR gas has tended to increase, and the amount of heat of exhaust gas tends to reach a high temperature, which has become a more serious problem.

Therefore, in order for the EGR valve 24 to be cooled by the traveling wind B, the EGR valve 24 is arranged on one side of the engine body 22 as shown by a phantom line in FIG. It is necessary to recirculate the EGR gas through the pipe 25, which causes a problem of high cost.

In view of such conventional problems, an object of the present invention is to provide an exhaust gas recirculation device that can prevent heat damage to an EGR valve and that is low in cost.

[0007]

[Means for Solving the Problems]

 The present invention relates to an exhaust gas recirculation device for supplying a part of exhaust gas into an intake manifold through an EGR valve, and a portion of a cylinder head or an intake manifold located on one side in a vehicle width direction of an engine room. The EGR valve is directly attached to the.

[0008] Preferably, an L-shaped first recirculation passage for guiding the exhaust gas from one side surface to which the exhaust manifold of the cylinder head is joined to the rear end surface and an intake manifold from the rear end surface of the cylinder head are joined together. An L-shaped second recirculation passage that guides the exhaust gas to the side surface and a third recirculation passage that communicates from one side surface of the cylinder head to the bent portion of the second recirculation passage and guides the exhaust gas to the other side surface are provided.

[0009]

[Action]

 According to the present invention, since the EGR valve is arranged on one side in the vehicle width direction of the engine room, the effect of cooling the EGR valve without being interrupted by the engine body is exerted, and the heat of the EGR valve is reduced. The harm can be reduced, and since the EGR valve is directly attached to the cylinder head or the intake manifold, no external piping is required and the cost can be reduced.

Further, by providing the first, second, and third recirculation passages in the cylinder head, the cylinder head can be shared for both a horizontal engine and a vertical engine.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a case of a horizontal engine. An engine body 2 is mounted in an engine room 1 with its crankshaft oriented horizontally in the vehicle width direction. An exhaust manifold 4 is connected to one side surface 3a on the front side of the cylinder head 3 of the engine body 2 in the direction A of the vehicle traveling direction, and an intake manifold 5 is connected to the other side surface 3b on the rear side. The rear end surface 3c of the cylinder head 3 is located on one side of the engine room 1 in the vehicle width direction, and the EGR valve 6 is directly attached to the rear end surface 3c of the cylinder head 3. Reference numeral 7a denotes a first recirculation passage that guides EGR gas from one side surface 3a of the cylinder head 3 to the rear end surface 3c, and 7b denotes a second recirculation passage that guides EGR gas from the rear end surface 3c to the other side surface 3b. Two ports of the EGR valve 6 are connected to the ports on the rear end surface 3c of the return passages 7a and 7b. In FIG. 1, B is a running wind, and 8 is a fan.

As shown in FIG. 3, the intake manifold 5 is provided with a plurality of branch pipes 10 extending from the collecting portion 9 so as to be connected to the intake ports of the cylinder head 3, and the cylinder heads are provided at their tip ends. 3, a mounting flange 11 for joining to the other side surface 3b of the cylinder head 3 is provided, and one end is connected to the opening of the second reflux passage 7b that opens on the other side surface 3b of the cylinder head 3, and the other end communicates with the collecting portion 9. An EGR gas recirculation passage 12 is provided.

On the other hand, FIG. 2 shows the case of a vertically installed engine. The engine body 2 is mounted in the engine room 1 with its crankshaft oriented vertically in the longitudinal direction of the vehicle. In this case, the engine body 2 is slanted in the vehicle width direction and is mounted with a slight inclination to the front and rear so as to be lowered rearward in the vehicle body front and rear direction. An exhaust manifold 14 is connected to one side surface 3a facing slightly downward, and an intake manifold 15 is connected to the other side surface 3b facing slightly upward. Therefore, when the EGR valve 6 is directly attached to the rear end surface 3c of the cylinder head 3 as shown in FIG. 1, the EGR valve 6 is located below the exhaust port on the upstream side of the exhaust gas flow, Condensation or carbon may enter the valve and cause functional problems. Therefore, in the case of a vertically installed engine, the EGR valve 6 is directly attached to the intake manifold 15 as in the conventional example. Reference numeral 7c is a third recirculation passage for guiding EGR gas from one side surface 3a of the cylinder head 3 to the other side surface 3b.

In this embodiment, the cylinder head 3 is shared by both the horizontal engine of FIG. 1 and the vertical engine of FIG. 2 so that the cylinder head 3 can be shared as shown in FIGS. A recirculation passage for EGR gas is formed in. 4 to 6, the first return passage 7a is L-shaped on the cylinder head 3 so that one port a opens on one side surface 3a of the cylinder head 3 and the other port b opens on the rear end surface 3c. It is formed by perforating. Further, the second return passage 7b is connected to the cylinder head 3 such that one port c is opened at a position above the rear end face 3c of the cylinder head 3 by an appropriate distance from the port b, and the other port d is opened on the other side face 3b. It is formed by perforating in an L shape. The third return passage 7c has one port e opened at an obliquely upper position of the port a on one side surface 3a of the cylinder head 3, and communicates with the second return passage 7b at a bent portion of the second return passage 7b. Thus, a part of the second return passage 7b is shared with the third return passage 7c.

With the above-described configuration, in the case of the horizontal engine shown in FIG. 1, the EGR valve 6 is directly attached to the rear end surface 3c of the cylinder head 3, and the inlet port of the EGR valve 6 is located at the port b and the outlet port is located at the outlet port. Are connected to port c, respectively. An exhaust manifold 4 configured to introduce a part of exhaust gas to the port a is connected to one side surface 3a of the cylinder head 3. The port e is sealed with a gasket arranged on the joint surface of the exhaust manifold 4 or another sealing plug. The intake manifold 5 is connected to the other side surface 3b of the cylinder head 3, and the port d is connected to the EGR gas recirculation passage 12 thereof. Thus, a part of the exhaust gas is recirculated into the intake air through the first recirculation passage 7a, the EGR valve 6, the second recirculation passage 7b, and the EGR gas recirculation passage 12 of the intake manifold 5.

Further, in the case of the vertically installed engine shown in FIG. 2, an exhaust manifold 14 configured to introduce a part of exhaust gas into a port e is connected to one side surface 3 a of the cylinder head 3 and the port a Is sealed with a gasket disposed on the joint surface of the exhaust manifold 14 or another sealing plug. An intake manifold 15 similar to the conventional example is connected to the other side surface 3b of the cylinder head 3, a port d is connected to the EGR gas recirculation passage, and an EGR valve 6 attached to the intake manifold 15 is connected to the EGR gas. It is installed in the middle of the return passage. A pair of bolt holes 16 for mounting the EGR valve 6 are provided on the rear end surface 3c of the cylinder head 3 as shown by phantom lines in FIG. 6 so as to be obliquely below the port b and obliquely above the port c. The engine hanger 17 is attached by utilizing it, and the port b and the port c are sealed by this engine hanger 17. Thus, a part of the exhaust gas is recirculated into the intake air through the third recirculation passage 7c, the EGR gas recirculation passage of the intake manifold 15 and the EGR valve 6.

Thus, in both the horizontal engine of FIG. 1 and the vertical engine of FIG. 2, the EGR valve 6 is arranged at one end in the vehicle width direction of the engine room 1, so that the running wind B is generated. The EGR valve 6 flows without being blocked by the engine body 2 and comes into contact with the EGR valve 6 to exert an effect of cooling the EGR valve 6. As a result, the heat damage to the EGR valve 6 can be reliably reduced. Further, since the EGR valve 6 is directly attached to the cylinder head 3 or the intake manifold 15, no external piping is required and the cost can be reduced.

In the above embodiment, since the cylinder head 3 can be commonly used in the case of the horizontally installed engine and the case of the vertically installed engine, the cost can be significantly reduced as compared with the case where the specifications are different. However, it goes without saying that another cylinder head configuration may be used.

[0020]

[Effect of device]

 According to the exhaust gas recirculation system of the present invention, since the EGR valve is arranged at one end in the vehicle width direction of the engine room as described above, the EGR valve can be effectively cooled by the running wind and the heat of the EGR valve can be reduced. It is possible to reduce the harm, and it is particularly effective when a large amount of EGR gas is recirculated. Also, since the EGR valve is directly attached to the cylinder head or the intake manifold, external piping is not required and low Can be configured at cost.

Further, by providing the first, second, and third recirculation passages in the cylinder head, the cylinder head can be shared for both a horizontal engine and a vertical engine, The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an exhaust gas recirculation apparatus according to an embodiment of the present invention applied to a horizontally mounted engine.

FIG. 2 is a schematic plan view of a state in which the exhaust gas recirculation device of the embodiment is applied to a vertically installed engine.

FIG. 3 is a plan view of an intake manifold in the case of the horizontal engine of the embodiment.

FIG. 4 is a perspective view showing a schematic configuration of a main part of a cylinder head that can be applied to both a horizontal engine and a vertical engine in the embodiment.

FIG. 5 is a front view of a main part of a cylinder head that can be applied to both a horizontal engine and a vertical engine in the embodiment.

6 is a view on arrow VV of FIG.

FIG. 7 is a schematic plan view showing a state in which an exhaust gas recirculation device of a conventional example is applied to a horizontal engine.

[Explanation of symbols]

 1 Engine Room 3 Cylinder Head 5 Intake Manifold 6 EGR Valve 7a First Recirculation Passage 7b Second Recirculation Passage 7c Third Recirculation Passage 15 Intake Manifold

Claims (2)

[Scope of utility model registration request] 1. An exhaust gas recirculation device for supplying a part of exhaust gas into an intake manifold via an EGR valve, wherein a cylinder head or an intake manifold located on one side in a vehicle width direction of an engine room. E on the part
An exhaust gas recirculation device characterized by having a GR valve directly attached. 2. An L-shaped first recirculation passage that guides exhaust gas from one side surface of the cylinder head where the exhaust manifold is joined to the rear end surface, and exhaust gas to the other side surface where the intake manifold is joined from the rear end surface of the cylinder head. An L-shaped second recirculation passage that guides gas and a third recirculation passage that communicates exhaust gas from the one side surface of the cylinder head to the bent portion of the second recirculation passage and guides exhaust gas to the other side surface are provided. The exhaust gas recirculation device according to claim 1.