JP2009127432A - Egr cooler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems as being unable to be correctly installed in a vehicle, due to deforming the whole EGR cooler, causing a crack, and dislocating a connecting position of a pipe of an exhaust gas inlet and an exhaust gas outlet and a pipe of a cooling water inlet and a cooling water outlet, since a shell is deformed when the shell cannot endure fastening force of a clamp, when installing the EGR cooler in the vehicle by using a clamp type bracket composed of an EGR cooler fixing member, a vehicle side installing bracket and the clamp. <P>SOLUTION: This EGR cooler is installed in the vehicle by the clamp type bracket. The shell is provided with a plurality of beads turning in the fastening direction of the clamp. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an EGR cooler that is fixed to a vehicle using a clamp-type bracket.

  Conventionally, an EGR cooler is configured to include a hollow shell having a cooling water inlet and a cooling water outlet, and a plurality of tubes through which EGR gas disposed inside the shell passes. In such an EGR cooler, a cooling water introduction pipe is installed in a vertical direction from the upper and lower surfaces or both side surfaces of the shell so as to introduce the cooling water into the shell. The cooling water in the shell flows from the cooling water inlet to the cooling water outlet between the tubes and between the shells and the tubes, and cools the EGR gas flowing into the tubes.

A conventional EGR cooler is provided with a bracket on a shell or a header, and the EGR cooler is attached to the vehicle by fixing the bracket and the vehicle side with a bolt or the like.
In such an EGR cooler, various measures are taken in order to prevent the engine from being damaged by the thermal stress accompanying the thermal expansion of each engine that occurs during heat exchange.

  Patent Document 1 discloses an EGR apparatus that includes an EGR cooler, an EGR valve that adjusts EGR gas, and an EGR pipe. An EGR cooler is mounted on a side surface of an exhaust manifold, and a coolant in the EGR cooler. By configuring the liquid level to be lower than the coolant level in the thermostat housing, the thermal load on the EGR cooler can be reduced and the cooler characteristics can be maintained, and the heat of the EGR valve can be improved. What can reduce the load is described.

  Further, in Patent Document 2, when an EGR cooler and an integrated bracket are attached to an object to be attached, a bolt hole formed in a long hole shape with respect to the longitudinal direction of the heat exchanger body is provided, and a bolt hole is provided in the bolt hole. Between the EGR cooler and the attached object by inserting a compressed elastic member between the bolt head and the bracket part to make the bracket and the attached object slidable. Even if there is a difference in thermal expansion, there is described a material that can alleviate thermal stress and prevent breakage.

  Further, in Patent Document 3, when the exhaust manifold and the EGR cooler are mounted close to each other, the exhaust manifold divided into a plurality of parts, the bracket that covers the upper surface of each exhaust manifold, and the EGR cooler are coupled to the upper surface of the bracket. A front stay and a rear stay are provided, and each exhaust manifold and bracket are positioned and fastened to a cylinder head at a predetermined mounting reference position, and the base portions of both stays are respectively connected to the mounting reference position and the exhaust manifold. By connecting to the bracket at the position matched in the length direction, the relative position to the EGR cooler will not change even if the manifold expands thermally, preventing excessive thermal stress, and the bracket to the EGR cooler It is possible to cut off heat It shall have been described.

JP 2000-282959 A JP2007-163015A Japanese Patent No. 3657524

Further, in recent years, parts are commonly used in order to reduce manufacturing costs. Therefore, the EGR cooler is not an EGR cooler provided with a dedicated mounting bracket for each vehicle, but the main body of the EGR cooler is the same as the mounting means. You can also see what has been devised for each vehicle.
For example, as shown in FIG. 8, a clamp-type bracket is prepared as a separate product, and there is a device that has been devised for attachment so that the same EGR cooler can be used in many vehicles.
The mounting means using the clamp type bracket has a high versatility of mounting because the bracket can be prepared as a separate part and the mounting position can be freely set, and is used for mounting various products. In addition, the fact that the shell deformation due to the thermal strain of the main body of the EGR cooler can be absorbed is one of the reasons employed.

  With regard to conventional mounting using such a clamp type bracket, the shell tube type EGR cooler with a small diameter has a round cross section, and generally the clamp type bracket is fixed to the shell of the EGR cooler. In the EGR cooler with a structure in which a plurality of flat tubes are arranged in parallel, which is often seen in recent EGR coolers, the shell has a quadrangular cross section. It cannot be said that there is sufficient rigidity. In particular, the EGR cooler, which has been enlarged in order to improve heat exchange performance, is heavy, and the area of the corner and the flat part of the shell is increased, so that the bending rigidity of the corner part and the surface rigidity of the flat part are insufficient. .

For this reason, in particular, when the EGR cooler 5 having the square shell 70 shown in FIG. 8 is fixed to the clamp type bracket 71, a force is applied to the shell 70 by the tightening force of the clamp 72 in the arrow direction, and the corner of the shell As a result, the side portion having a large number of flat portions and the flat portion cannot endure, the shell in the range E is deformed, and the EGR cooler 5 and the bracket 71 are not correctly attached. Further, the deformation of the shell 70 causes the entire EGR cooler 5 to be deformed and cracked, and the connection positions of the exhaust gas inlet and exhaust gas outlet pipes, the cooling water inlet and cooling water outlet pipes are shifted, and the vehicle is correctly connected. There were also cases where it could not be installed.
Further, when fixing the EGR cooler with a clamp, it takes time to position the EGR cooler in the longitudinal direction in order to determine the correct fixing position.

The subject of this invention is providing the structure which prevents a deformation | transformation of the shell of an EGR cooler by the clamping force of a clamp, when fixing an EGR cooler to a vehicle with a clamp type bracket.
Another problem is to facilitate positioning of the position where the clamp is attached when the EGR cooler is fixed by the clamp.

In the present invention, means for effectively solving the above-described problem is as follows. The invention of claim 1 is a plurality of EGR coolers that are attached to a vehicle by a clamp-type bracket. It is characterized by providing a bead.

  According to a second aspect of the present invention, in the EGR cooler according to the first aspect, the bead is provided continuously over the entire circumference of the shell.

  The invention according to claim 3 is the EGR cooler according to claim 1, wherein two U-shaped plates are joined at the joint of the upper and lower surfaces, and the bead is placed on the upper and lower surfaces of the EGR cooler in which a square shell is formed. It is characterized by being continuously provided around the shell excluding the joint portion.

  According to a fourth aspect of the present invention, in the EGR cooler according to the second or third aspect, the bead is a convex bead toward the outside of the shell, and is provided close to both sides of the position of the shell to which the clamp is attached. It is characterized by that.

  According to a fifth aspect of the present invention, in the EGR cooler according to the second or third aspect, the bead is a concave bead toward the outside of the shell, and is provided at a position corresponding to the center of the position of the shell to which the clamp is attached. It is characterized by that.

  According to the first aspect of the present invention, by providing the EGR cooler shell with a plurality of beads directed in the clamping direction of the clamp, the rigidity of the portion where the beads are installed is increased, so that the clamping force by the clamp can be sufficiently resisted. The deformation of the shell can be prevented, the entire EGR cooler is deformed, cracks are generated, the connection positions of the exhaust gas inlet / outlet pipe and the cooling water inlet / outlet pipe are misaligned and cannot be correctly attached to the vehicle. Can be eliminated.

  Moreover, when adjusting the clamping force of a clamp by the magnitude | size, vibration, etc. of an EGR cooler main body, it can respond by adjusting bead height or bead width.

  In addition, by providing multiple beads on the shell, the area of the plane between the beads can be reduced and the plane accuracy of the contact surface of the clamp can be increased. It became possible.

  According to the invention according to claim 2, by providing the bead continuously over the entire circumference of the shell, the rigidity of the portion where the bead is installed is increased, and can sufficiently withstand the tightening force by the clamp. , Prevents deformation of the shell, the entire EGR cooler is deformed, cracks are generated, and the exhaust gas inlet / outlet pipe and cooling water inlet / outlet pipe connection position shifts, preventing problems such as being unable to attach correctly to the vehicle can do.

  According to the invention of claim 3, in the EGR cooler in which two U-shaped plates are joined at the joint portions of the upper and lower surfaces to form a square shell, the plurality of beads directed in the clamping direction of the clamp are By providing it continuously around the shell excluding the joint part, it is possible to join the plates without gaps when joining the U-shaped plate compared to the case where beads are provided over the entire circumference including the joint part. The man-hour for adjusting the position, height and width of the bead can be saved.

  According to the invention of claim 4, the convex bead is provided toward the outside of the shell so as to be close to both sides of the position of the shell to which the clamp is attached, so that the position of the shell to which the clamp is attached becomes clear. , Positioning can be facilitated.

  According to the fifth aspect of the present invention, the concave bead is provided toward the outside of the shell at the portion of the shell corresponding to the center of the position of the shell to which the clamp is attached, so that the position of the shell to which the clamp is attached is clearly defined. Thus, positioning can be facilitated.

Hereinafter, the EGR cooler according to the first embodiment of the present invention will be described.
The EGR cooler 1 according to this example is an EGR cooler including a square shell 10 as shown in FIG. 1, and includes a cooling water inlet 12 and a cooling water outlet 13. The exhaust gas in the tube flowing in from the gas inlet 14 is cooled and discharged from the exhaust gas outlet 15.

As shown in FIG. 3, the shell 10 of the EGR cooler 1 is a combination of two U-shaped plates formed by processing metal plates and joined at joints 32 and 33, and the lower side, upper side, one side, It is formed in a square cylinder shape having other side surfaces. The inside has a structure in which a large number of flat tubes 34 through which exhaust gas flows are arranged in parallel, and dowels 35 are arranged between the tubes and between the tubes and the shell to provide a gap. .
In this example, as shown in FIG. 1, regarding attachment to a vehicle body, a clamp-type attachment bracket 4 as shown in FIG. 7 is prepared as a separate product and attached to the vehicle body using this.

As shown in FIG. 7, the clamp-type mounting bracket 4 includes an upper U-shaped EGR cooler fixing member 21 and a lower vehicle-side mounting bracket 20 that are gathered together by a steel clamp 22. The clamp is provided with a clamp tightening bolt 23 and a nut 24, and the clamp 22 is tightened by tightening the clamp tightening bolt 23.
The EGR cooler fixing member 21 and the vehicle side mounting bracket 20 are provided with relief portions 25 and 26 of the shell joint portion at the center portion of the portion in contact with the shell 10 so that the upper surface and the lower surface of the shell 10 are not wobbled. And is clamped with a vertical force by a clamp 22.

The dimension C of the U-shaped EGR cooler fixing member 21 and the dimension D of the vehicle side mounting bracket 20 described in FIG. 7 are set slightly larger than the width of the EGR cooler 1, The EGR cooler 1 does not rattle and is easily pinched.
Further, guides are provided on both ends of the EGR cooler fixing member 21 and the vehicle side mounting bracket 20 so that the clamps are not displaced.

  In this example, as shown in FIG. 2, convex beads 16, 17, 18, and 19 facing the outside of the shell are positioned at both sides close to the clamp mounting surfaces 30 and 31 in the same direction as the clamp 22 is tightened. In the direction, press the entire circumference of the shell. In this example, in order to fix the EGR cooler by clamp type brackets at two locations, a total of four convex beads are provided.

  In this example, when the EGR cooler 1 is attached to the vehicle body by the clamp type mounting bracket 4, the clamping surface of the clamp 22 is arranged on the clamp mounting surfaces 30 and 31 between the convex beads provided on the shell 10, and the clamp Tightening is performed with a predetermined tightening torque by 22 tightening bolts 23.

  In such an embodiment, by providing the convex beads 16, 17, 18, 19 in the same direction as the clamping direction of the clamp, the surface rigidity of the surface portion where the beads are installed and the bending rigidity of the corner portion are increased. It will be able to withstand the tightening force by the clamp 22 and the deformation of the shell 10 can be prevented, the entire EGR cooler is deformed, cracks occur, and the exhaust gas inlet / outlet pipe and the cooling water inlet / outlet pipe are connected at different positions. It is possible to solve the problem that the vehicle cannot be correctly attached to the vehicle.

  By providing a plurality of beads, the area between the beads can be reduced, and the plane accuracy of the mounting surfaces 30 and 31 of the clamps can be increased. Therefore, the clamps 22 and the shell 10 can be properly contacted and attached with a good tightening force. It becomes possible.

  By providing convex beads toward the outside of the shell at the positions on both sides close to the clamp mounting surfaces 30 and 31, over the entire circumference of the shell in the same direction as the clamping direction of the clamp, the clamp mounting surface Since 30 and 31 can be easily grasped, it is not necessary to position the EGR cooler in the longitudinal direction, and the clamp-type mounting bracket 4 can be easily attached.

  When the clamping force of the clamp is adjusted by the size of the EGR cooler body, vibration, or the like, it can be dealt with by adjusting the height of the bead or the width of the bead.

Another embodiment is shown below.
[Second Embodiment]
In the first embodiment, convex beads 16, 17, 18, and 19 are disposed at positions on both sides close to the clamp mounting surfaces 30 and 31, with the same direction as the clamp tightening direction. 10, the convex bead does not have to extend over the entire circumference of the shell 10, and the convex beads 46, 47, 48, 49, 50, shown in FIGS. Like 51,52,53, you may provide continuously in the circumference | surroundings of the shell except the junction parts 57 and 58 vicinity of an up-and-down surface.

  In this case, convex beads 46, 47, 48, 49, 50, 51, 52, 53 facing the clamping direction of the clamp are continuously provided around the shell except for the joint portions 57, 58 on the upper and lower surfaces of the shell. As a result, the position, height, and width of the beads for joining the U-shaped plates without gaps are adjusted when joining the U-shaped plates as compared with the case where beads are provided over the entire circumference including the joining portions 57 and 58. Man-hours can be saved.

[Third embodiment]
In the first embodiment, convex beads 16, 17, 18, and 19 are provided toward the outside of the shell at positions on both sides close to the clamp mounting surfaces 30 and 31 of the shell as positioning means. As shown in FIG. 6, a concave bead 62 may be provided toward the outside of the shell at the center of the position where the shell clamp is attached. In this case, the same number of concave beads as the place where the EGR cooler 3 is fixed by the clamp-type mounting bracket 63 is provided. For example, when the EGR cooler is fixed to the bracket at two locations, a total of two concave beads are provided.

  When the EGR cooler 3 is attached to the vehicle body by the clamp type mounting bracket 63, the center portion of the clamp type mounting bracket 63 is aligned with the concave bead 62 provided on the shell 60, and a predetermined tightening is performed by the tightening bolt 23 of the clamp 22. Tighten with torque.

  In this case, since the concave bead 62 is provided toward the outside of the shell at the center of the position where the shell clamp is attached, the shell clamp attachment position can be easily grasped, so that the EGR cooler is positioned in the longitudinal direction. There is no need to do so, and the clamp-type mounting bracket 63 can be easily attached.

[Other aspects]
You may increase the attachment position by a clamp according to the length and vibration of an EGR cooler.
Further, the bead may be provided with an optimal length and position where the surface rigidity is increased in a place where deformation due to clamping of the clamp occurs, instead of being provided on both sides of the clamp or in the center of the mounting portion depending on the shape of the EGR cooler. .
Further, not only the EGR cooler having a square shell but also a shell tube type EGR cooler having a large diameter using a clamp type bracket may be provided with a bead if the rigidity is insufficient.
In FIG. 7, the vehicle-side mounting bracket is shown as an integrated type, but a separate clamp-type bracket in which the clamp and the vehicle-side mounting bracket are paired, and depending on the size and length of the EGR cooler and the vibration of the vehicle, The number may be increased as necessary.

It is a top view which shows the state which attached the EGR cooler which concerns on 1st Embodiment of this invention to the bracket. It is a perspective view of the EGR cooler. It is sectional drawing in the AA line in FIG. 2 which shows the structure of the same EGR cooler. It is a perspective view of the EGR cooler concerning a 2nd embodiment of the present invention. It is sectional drawing in the BB line in FIG. 4 which shows the structure of the same EGR cooler. It is an enlarged plan view which shows the bracket attachment position in the EGR cooler which concerns on 3rd Embodiment of this invention. It is a perspective view of the clamp type attachment bracket attached to an EGR cooler in a 1st embodiment of the present invention. It is an enlarged plan view which shows the bracket attachment position in the EGR cooler provided with the conventional square shell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 EGR cooler 10 Shell 11a, 11b Header 12 Cooling water inlet 13 Cooling water outlet 14 Exhaust gas inlet 15 Exhaust gas outlet 16, 17, 18, 19 Convex bead 4 Clamp type mounting bracket 20 Vehicle side mounting bracket 21 EGR cooler Fixing member 22 Clamp 23 Clamp tightening bolt 24 Nut 25, 26 Shell joint relief 30, 31 Shell clamp mounting surface 32, 33 Joint 34 Tube 35 Dowel 36a, 36b Flange 2 EGR cooler 40 Shell 41a, 41b Header 42 Cooling water inlet 43 Cooling water outlet 44 Exhaust gas inlet 45 Exhaust gas outlet 46, 47, 48, 49, 50, 51, 52, 53 Convex bead 54, 55 Shell clamp mounting surface 56a, 56b Flange 57, 58 Joint 3 EGR cooler 60 Shell 61 Header 62 Concave bead 63 Clamp type mounting bracket 5 EGR cooler 70 Shell 71 Clamp type mounting bracket 72 Clamp

Claims (5)

  An EGR cooler that is attached to a vehicle with a clamp type bracket, wherein the shell is provided with a plurality of beads directed in a clamping direction of the clamp.   The EGR cooler according to claim 1, wherein the beads are continuously provided over the entire circumference of the shell.   In the EGR cooler in which two U-shaped plates are joined at the upper and lower joints to form a square shell, the beads are continuously provided around the shell excluding the upper and lower joints. The EGR cooler according to claim 1, wherein the EGR cooler is characterized.   4. The EGR cooler according to claim 2, wherein the bead is a convex bead toward the outside of the shell, and is provided so as to be close to both sides of the position of the shell to which the clamp is attached.   4. The EGR cooler according to claim 2, wherein the bead is a concave bead toward the outside of the shell, and is provided at a position corresponding to a center of a position of the shell to which the clamp is attached.

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