Exhaust treatment apparatus

An exhaust treatment apparatus has an arm rotatably supported on a test bed and a masking section provided at the distal end portion of the arm. The masking section is connected to an exhaust treatment section via an exhaust pipe. When the arm is turned to a test position from a standby position, the masking section faces an internal combustion engine with a predetermined gap therebetween. In this state, a masking-section cylinder presses the masking section toward the internal combustion engine to set the masking section in close contact with the internal combustion engine. As a result, the exhaust port of the internal combustion engine is connected to an inlet port provided in the masking section. Exhaust gas discharged from the exhaust port is supplied to the exhaust treatment section through the inlet port, the masking section and the exhaust pipe, and is treated in the exhaust treatment section.

BACKGROUND OF THE INVENTION

The present invention relates generally to an exhaust treatment apparatus which treats exhaust discharged from an internal combustion engine when the engine is being tested.

At the time of manufacturing an internal combustion engine, a test for detecting assembly defects and the like is performed after predetermined stages. As this test is basically conducted while the internal combustion engine is running, it is necessary to treat exhaust gas discharged from the internal combustion engine. It is therefore typical to connect the internal combustion engine to be tested to an exhaust treatment apparatus for treating the exhaust gas from the engine via an exhaust manifold.

However, because the attachment and detachment of the exhaust manifold is generally done manually by a worker, conventional tests on internal combustion engines face an issue of low work efficiency. In addition, the exhaust manifold cannot be detached from the internal combustion engine until the heat from the exhaust manifold, which has become hot due to the exhaust gas from the internal combustion engine, has sufficiently discharged. To continuously conduct tests on multiple internal combustion engines on an assembly line in a factory, it is therefore necessary to prepare a plurality of exhaust manifolds and use the manifolds one after another. This inevitably increases the number of steps for attaching and detaching the exhaust manifolds and the cost for the manifolds.

Prior art documents pertinent to the present invention are Japanese Patent Laid-Open Publication No. Sho 63-38877/1988 and Japanese Patent Laid-Open Publication No. Hei 10-239216. Japanese Patent Laid-Open Publication No. Sho 63-38877 discloses a technique relating to a test on an internal combustion engine in a low-temperature test room but fails to disclose treatment for exhaust gas discharged from the internal combustion engine at the time the engine is tested. Japanese Patent Laid-Open Publication No. Hei 10-239216 merely discloses a technique relating to a fatigue test on an exhaust manifold that is used for an internal combustion engine, but fails to disclose a test on the internal combustion engine itself.

SUMMARY OF THE INVENTION

Accordingly, it is a primary objective of the present invention to provide an exhaust treatment apparatus capable of testing an internal combustion engine with high work efficiency.

To achieve the objective, the present invention provides an exhaust treatment apparatus which treats exhaust) discharged from an exhaust port of an internal combustion engine when testing the internal combustion engine, and comprises an exhaust inlet portion having an inlet port through which exhaust discharged from the exhaust port is introduced, and a displacement mechanism which displaces the exhaust inlet portion in such a way as to set the inlet port close to and away from the exhaust port.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first embodiment of the invention is described below with reference toFIGS. 1 to 7. An exhaust treatment apparatus1according to this embodiment is constructed in such a way so as to cope with an internal combustion engine E which has cylinders laid out in a V shape.

Referring toFIGS. 1 to 3, the general structure of the exhaust treatment apparatus1is described first. At the time an internal combustion engine E is tested using the exhaust treatment apparatus1, the internal combustion engine E is clamped by a clamp mechanism22provided on a test bed21and fixed at a position indicated by a two-dot chain line inFIGS. 1 to 3. The clamp mechanism22functions as a restriction mechanism which restricts the rocking of the internal combustion engine E when the internal combustion engine E runs.

Provided on the test bed21are a pair of arm mounting sections31to each of which an arm32is rotatably attached via an arm pivot portion32a. The arm mounting section31is constructed in such a way that the center axis, C, of the arm pivot portion32ahas a predetermined inclination corresponding to the shape of the internal combustion engine E with respect to the test bed21.

An exhaust inlet portion or a masking section33, which is connected to the internal combustion engine E and into which the exhaust gas from the engine E is led, is provided at the distal end portion of each arm32or an arm distal end portion32b. Each masking section33is coupled to the associated arm distal end portion32bvia a masking-section cylinder34comprised of a hydraulic cylinder. The masking section33can be set in close contact with the internal combustion engine E via the pressure applied on the masking section33by the cylinder34.

Each masking section33is attachable to and detachable from the associated arm distal end portion32b. Each of the arms32and the masking sections33is covered with a heat insulator35.

Each arm32is coupled to an arm cylinder38, comprised of a hydraulic cylinder and provided at the test bed21. Each arm32is moved by the associated cylinder38in such a way as to draw an arcuate locus with the center axis C of the arm pivot portion32aas a rotational axis.

Each arm32rotates in such a way that the arm distal end portion32bmoves close to and away from an associated exhaust port Exp of the internal combustion engine E. Specifically, each arm32rotates between a position indicated by a solid line inFIGS. 1 to 3(position closest to the internal combustion engine E) and a position indicated by a two-dot chain line (position farthest from the internal combustion engine E) as indicated by the arrow A. Hereinafter, the position of the arm32closest to the internal combustion engine E is called a “test position” and the position of the arm32farthest from the internal combustion engine E is called a “standby position”.

The test position and the standby position are set as follows. That is, the test position is set at the position where a predetermined gap G is provided between each of a plurality of inlet ports33aprovided at each masking section33and the associated exhaust port Exp of the internal combustion engine E. The standby position is set at the position where each arm32does not interfere with the carry-in/carry-out of the internal combustion engine E.

A plurality of inlet ports33aprovided at each masking section33respectively correspond to the plurality of exhaust ports Exp provided at one side of the internal combustion engine E. A masking plate36(seal member) formed of a fluorine-based rubber material is attached to an end face of each masking section33having those inlet ports33aarranged in such a way as to surround the inlet ports33a. At the time each masking section33is connected to the internal combustion engine E, the masking plate36adequately seals connected portions between the exhaust ports Exp and the associated inlet ports33a.

The masking section33is connected to the internal combustion engine E in the following manner. As the masking section33is pressed toward the internal combustion engine E by the masking-section cylinder34with each arm32being at the test position, the predetermined gap G disappears, thus connecting the inlet ports33ato the associated exhaust ports Exp.

The masking section33takes a floating structure. While being connected to the internal combustion engine E, the masking section33having the floating structure blocks transmission of vibration to the arm32from the internal combustion engine E. Further, the masking plate36, which is resilient, absorbs the vibration of the internal combustion engine E in such a way as to suppress transmission of the vibration to the masking section33.

The masking sections33are connected via flexible exhaust pipes37to an exhaust treatment section4which treats the exhaust gases discharged from the exhaust ports Exp of the internal combustion engine E. Therefore, the exhaust gas discharged from each exhaust port Exp flows inside the exhaust treatment apparatus1in the order of the associated inlet port33a, the associated masking section33, the associated exhaust pipe37and the exhaust treatment section4. The exhaust treatment section4treats the exhaust gas from the internal combustion engine E by an appropriate known method.

In the present embodiment, the arms32, the arm cylinders38and the masking-section cylinders34constitute a displacement mechanism and the masking-section cylinders34function as a pressing mechanism.

Next, the test mode of the internal combustion engine E by the exhaust treatment apparatus1is described with reference toFIGS. 4 to 7. The internal combustion engine E is tested in the following steps 1 to 8.

Step 1: As shown inFIG. 4, both arms32are held at the standby position by the associated arm cylinders38before the internal combustion engine E is brought into the exhaust treatment apparatus1.

Step 2: As shown inFIG. 5, the internal combustion engine E is carried in by a pallet P and the engine E is then clamped by the clamp mechanism22.

Step 3: As shown inFIG. 6, the arms32are rotated to the test position by the associated arm cylinders38and are held at the test position. At this time, the inlet ports33aof each masking section33face the associated exhaust ports Exp of the internal combustion engine E at the predetermined gap G.

Step 4: As shown inFIG. 7, the masking section33is pressed toward the internal combustion engine E by the associated masking-section cylinder34and the inlet ports33aof the masking section33are connected to the associated exhaust ports Exp.

Step 5: The internal combustion engine E is started in the state shown inFIG. 7and a test is conducted by an inspector as to whether or not there are problems with the engine E including abnormal noise, defective assemblage and oil leakage. At this time, the exhaust gas produced by the running of the internal combustion engine E flows in the order of the exhaust ports Exp, the inlet ports33a, the masking sections33, the exhaust pipes37and the exhaust treatment section4and is treated in the exhaust treatment section4.

Step 6: After the test on the internal combustion engine E is finished, the masking sections33are separated from the internal combustion engine E by the associated masking-section cylinders34by disconnecting the inlet ports33afrom the exhaust ports Exp, as shown inFIG. 6.

Step 7: As shown inFIG. 5, the arms32are pulled back to the standby position from the test position by the associated arm cylinders38and held at the standby position.

Step 8: As shown inFIG. 4, the clamping of the internal combustion engine E by the clamp mechanism22is released and the internal combustion engine E is then carried out on the pallet P.

After the test on one internal combustion engine is conducted via the steps 1 to 8, another internal combustion engine is carried in and the same procedures as in the steps 1 to 8 are repeated.

As apparent from the above, this embodiment has the following advantages.

(1) The arms32, the arm cylinders38and the masking-section cylinders34which constitute the displacement mechanism function to connect the masking sections33to the internal combustion engine E. At the time the internal combustion engine E is tested, this embodiment eliminates the need for an exhaust manifold that is needed in the prior art. This can lead to reduction in the cost needed for testing the internal combustion engine E. The use of the exhaust treatment apparatus1according to this embodiment in testing the internal combustion engine E can ensure preparation of the test without requiring manual work by a worker. Unlike in the prior art, the embodiment does not require work for attachment and detachment of an exhaust manifold with respect to an internal combustion engine. Therefore, the embodiment can test the internal combustion engine E with high efficiency.

(2) The masking-section cylinder34presses the associated masking section33toward the internal combustion engine E. Accordingly, the inlet port33aof the masking section33is adequately placed in close contact with the associated exhaust port Exp of the internal combustion engine E, thus adequately suppressing leakage of the exhaust gas to the outside.

(3) The arm32and the masking section33are covered with the heat insulator35. This suppresses a rise in the surface temperatures of the arm32and the masking section33and heat radiation from the arm32and the masking section33. At the time the internal combustion engine E is tested, therefore, an inspector can properly view the status of the internal combustion engine E at a position relatively close to the engine E.

(4) The arm32is moved by the associated cylinder38in such a way as to draw an arcuate locus with the arm pivot portions32aas the center axis. This can permit an inspector to come closer to the internal combustion engine E, thereby more suitably guaranteeing visibility for the inspector with respect to the internal combustion engine E.

(5) Conventionally, at the time of testing an internal combustion engine, an exhaust manifold equipped on a vehicle or an exhaust manifold for a test is connected to the internal combustion engine. Because such an exhaust manifold generally has a complex shape, the visibility of that side portion of the internal combustion engine where the exhaust manifold is connected at the time of testing the engine is not secured sufficiently. As the masking section33is designed to be more compact than the exhaust manifold and is connected to an internal combustion engine according to the exhaust treatment apparatus1of this embodiment, the visibility for a worker can be guaranteed suitably.

(6) While being connected to the internal combustion engine E, the masking section33having a floating structure blocks transmission of vibration to the arm32from the engine E. At least that portion of the masking section33which is connected to the internal combustion engine E (the portion to which the masking plate36is attached) is floating with respect to the remaining portion, and can therefore move together with the internal combustion engine E in response to the vibration of the engine E during engine running. Even while the internal combustion engine E is running under a test, therefore, the connection between the engine E and the masking section33is maintained properly, thus advantageously suppressing leakage of the exhaust gas.

(7) The masking plate36formed of a fluorine-based rubber material is provided around the inlet ports33aof each masking section33. As the connected portions between the inlet ports33aand the exhaust ports Exp are sealed with the masking plate36formed of a fluorine-based rubber material having high heat resistance, leakage of the exhaust gas is suppressed properly. In addition, the synergism of this advantage with the advantage described in (6) can suppress the transmission of vibration to the arm32from the internal combustion engine E more properly.

(8) The masking sections33are connected via the flexible exhaust pipes37to the exhaust treatment section4. This can increase the degree of freedom in designing the exhaust treatment apparatus1including the shape and layout and the like of the exhaust pipes37.

(9) The masking section33is attachable to and detachable from the associated arm distal end portion32b. Therefore, the masking section33can be replaced with a proper one in accordance with the shape of the internal combustion engine. This can increase the versatility of the exhaust treatment apparatus1.

(10) The arms32and the arm cylinders38are provided on the test bed21. As a result, the overall size of the exhaust treatment apparatus1becomes relatively small.

(11) The internal combustion engine E is clamped by the clamp mechanism22provided on the test bed21. At the time of testing the internal combustion engine E, therefore, the engine E can be kept stable.

(12) At the time the inlet ports33aof the masking section33are connected to the exhaust ports Exp of the internal combustion engine E, the arm32is moved to the test position and the masking section33is then pressed toward the internal combustion engine E by the masking-section cylinder34. This suppresses shocks generated when the masking section33is connected to the internal combustion engine E to advantageously avoid damage to bolts and the like provided around the exhaust port Exp, as compared with a case where the masking section33is connected to the engine E merely by moving the arm32.

(13) The masking sections33of the pair of arms32are connected to the internal combustion engine E in such a way as to grab the internal combustion engine E. This can permit the internal combustion engine E to be maintained stably at the time of testing the engine E.

Referring now toFIGS. 8 to 10, the second embodiment of the present invention is described, centering on the differences from the first embodiment inFIGS. 1 to 7. The exhaust treatment apparatus1according to the second embodiment is constructed in such a way so as to cope with an internal combustion engine E having inline cylinders.

The exhaust treatment apparatus1of this embodiment differs from that of the first embodiment inFIGS. 1 to 7in the following points. That is, the arm mounting section31is constructed in such a way that the center axis C of the arm pivot portion32aintersects the test bed21approximately perpendicularly in accordance with the shape of the internal combustion engine E, as shown inFIGS. 8 to 10.

Further, two arms32are provided on the test bed21in the first embodiment inFIGS. 1 to 7, whereas the arm32is provided only on that side which corresponds to the exhaust ports Exp of the internal combustion engine E in the second embodiment. The arm32, like the arm32in the first embodiment inFIGS. 1 to 7, has the masking section33at the arm distal end portion32band the masking section33is coupled to the arm distal end portion32bvia the masking-section cylinder34.

In the exhaust treatment apparatus1of this embodiment, the internal combustion engine E is also tested according to the procedures of steps 1 to 8 described in the foregoing description of the first embodiment inFIGS. 1 to 7. The second embodiment therefore has advantages similar to the above-described advantages 1 to 12 of the first embodiment inFIGS. 1 to 7.

Although the arm32is provided only on that side which corresponds to the exhaust ports Exp of the internal combustion engine E inFIGS. 8 to 10, the structure may be modified as follows. Like the structure of the first embodiment inFIGS. 1 to 7, another arm facing the arm32inFIGS. 8 to 10may be provided with an internal combustion engine E in between the two arms so that the internal combustion engine E is held by both arms. This modification can keep the internal combustion engine E more stable as compared with the case where only a single arm is provided. It is of course unnecessary to provide an inlet port on or connect an exhaust pipe to that masking section which is provided on the arm that does not correspond to the exhaust ports Exp of the internal combustion engine E.

The third embodiment of the present invention is described below with reference toFIGS. 11 to 15. The exhaust treatment apparatus1according to this embodiment is constructed in such a way so as to cope with an internal combustion engine E that has cylinders laid out in a V shape. The same reference symbols are given to those members which have the same functions as the corresponding members of the first embodiment inFIGS. 1 to 7.

The general structure of the apparatus1is discussed first with reference toFIG. 11. At the time the internal combustion engine E is tested using the exhaust treatment apparatus1, the internal combustion engine E is clamped by the clamp mechanism22provided on the test bed21and is fixed at a position indicated by a two-dot chain line inFIG. 11.

A slide mechanism5is provided upright on the test bed21and a gate-shaped arm32is attached to the slide mechanism5. The slide mechanism5has an actuator to lift the arm32up and down. The masking sections33that function as exhaust inlet portions are respectively provided at the two distal end portions of the gate-shaped arm32or both arm distal end portions32b. Each masking section33is coupled to the associated arm distal end portion32bvia the associated masking-section cylinder34. Each masking section33is attachable to and detachable from the associated arm distal end portion32b. Each of the arm32and both masking sections33is covered with the heat insulator35.

The arm32is moved up and down with respect to the test bed21by the slide mechanism5. The arm32is lifted up and down in such a way that both arm distal end portions32bmove close to and away from the associated exhaust ports Exp of the internal combustion engine E. Specifically, the arm32is lifted up and down between a position indicated by a solid line inFIG. 11(position closest to the internal combustion engine E9) and a position indicated by a two-dot chain line (position farthest from the internal combustion engine E). Hereinafter, the position of the arm32closest to the internal combustion engine E is called a “test position” and the position of the arm32farthest from the internal combustion engine E is called a “standby position”.

The test position and the standby position are set in the same way as those in the first embodiment inFIGS. 1 to 7. That is, the test position is set at the position where a predetermined gap G is provided between each of a plurality of inlet ports33aprovided at each masking section33and the associated exhaust port Exp of the internal combustion engine E. The standby position is set at the position where each arm32does not interfere with the carry-in/carry-out of the internal combustion engine E.

A masking plate36similar to the one in the first embodiment inFIGS. 1 to 7is attached to each masking section33. As the masking section33is pressed toward the internal combustion engine E (the direction of the arrow B inFIG. 11) by the masking-section cylinder34with the arm32being at the test position, the predetermined gap G disappears, with the result that the inlet ports33aare connected to the associated exhaust ports Exp. As in the first embodiment inFIGS. 1 to 7, the masking section33has a floating structure and is connected to the exhaust treatment section4via the flexible exhaust pipe37.

In this embodiment, the arm32, the masking-section cylinders34and the slide mechanism5constitute the displacement mechanism and the masking-section cylinders34function as the pressing mechanism.

Referring toFIGS. 12 to 15, the test mode of the internal combustion engine E by the exhaust treatment apparatus1is discussed. The internal combustion engine E is tested in the following steps 1 to 8.

Step 1: As shown inFIG. 12, the arm32is held at the standby position by the slide mechanism5before the internal combustion engine E is carried into the exhaust treatment apparatus1.

Step 2: As shown inFIG. 13, the internal combustion engine E is carried in by a predetermined device and the engine E is then clamped by the clamp mechanism22.

Step 3: As shown inFIG. 14, the arm32is moved to the test position by the slide mechanism5and held at the test position. At this time, the inlet ports33aof each masking section33face the associated exhaust ports Exp of the internal combustion engine E at the predetermined gap G.

Step 4: As shown inFIG. 15, the masking section33is pressed toward the internal combustion engine E by the associated masking-section cylinder34so that the inlet ports33aare connected to the associated exhaust ports Exp.

Step 5: The internal combustion engine E is started in the state shown inFIG. 15and a test is conducted by an inspector as to whether or not there are problems with the engine E including abnormal noise, defective assemblage and oil leakage. At this time, the exhaust gas produced by the running of the internal combustion engine E flows in the order of the exhaust ports Exp, the inlet ports33a, the masking sections33, the exhaust pipes37and the exhaust treatment section4and is treated in the exhaust treatment section4.

Step 6: After the test on the internal combustion engine E is finished, the masking sections33are separated from the internal combustion engine E by the associated masking-section cylinders34, by disconnecting the inlet ports33afrom the exhaust ports Exp, as shown inFIG. 14.

Step 7: As shown inFIG. 13, the arm32is pulled back to the standby position from the test position by the slide mechanism5and held at the standby position.

Step 8: As shown inFIG. 12, the clamping of the internal combustion engine E by the clamp mechanism22is released and the internal combustion engine E is then carried out by the predetermined device.

After the test on one internal combustion engine is conducted through the steps 1 to 8, another internal combustion engine is carried in and the same procedures in the steps 1 to 8 are repeated.

The third embodiment discussed above in detail has advantages similar to the above-described advantages 1 to 13 of the first embodiment inFIGS. 1 to 7. Particularly, as the slide mechanism5which supports the arm32is provided upright on the test bed21, the mounting area for the exhaust treatment apparatus1can be small.

The individual embodiments can be modified as follows.

In the first and second embodiments, the arm32and the arm cylinder38may be provided separate from the test bed21. In the third embodiment, the slide mechanism5may be provided separate from the test bed21. In those cases, the test bed21may be omitted. In a case where the test bed21is not provided, however, it is desirable to clamp an internal combustion engine and restrict the engine by an adequate clamp mechanism used in place of the clamp mechanism22on the test bed21.

In the first and second embodiments, the arm32may be driven by an actuator other than a hydraulic cylinder. In the third embodiment, a hydraulic cylinder or various other kinds of actuators can be adapted too as an arm actuator provided on the slide mechanism5. Further, the masking-section cylinder34in the first to third embodiments may be changed to an actuator other than a hydraulic cylinder.

In the first and second embodiments, the masking-section cylinder34may be omitted. In this case, the masking section33is connected to an internal combustion engine E only by the movement of the arm32done by the arm cylinder38. That is, the arm32and the arm cylinder38alone constitute the displacement mechanism from which the masking-section cylinder34is excluded.

In the first and second embodiments, the masking-section cylinder34may be excluded from the components of the displacement mechanism and may function only as the pressing mechanism. That is, the masking section33may be connected to an internal combustion engine E only by the movement of the arm32done by the arm cylinder38and may then be pressed toward the internal combustion engine E by the masking-section cylinder34.

In the first to third embodiments, the masking section33may be attached to the arm distal end portion32bin an undetachable manner or the masking section33may be formed integral with the arm distal end portion32b.

In the first to third embodiments, the heat insulator35which covers the arm32and masking section33may be omitted.

In the first to third embodiments, the masking section33may not take a floating structure.

In the first to third embodiments, the masking plate36may be formed of a material other than a fluorine-based rubber material. It is particularly preferable that the masking plate36be formed of a resilient material having heat resistance. The masking plate36may be omitted.

In the first to third embodiments, the exhaust pipe37may be constructed in such a way as to pass through the arm32.

In the first to third embodiments, in place of the masking-section cylinder34, a pressing mechanism for pressing the masking section33may be provided separate from the arm32.

The exhaust treatment apparatus according to the invention is not limited to the use in the case where an internal combustion engine is tested while the internal combustion engine is combusting fuel, but may be adapted to a so-called motoring test to test an internal combustion engine E while the internal combustion engine is not combusting fuel. In the case where an internal combustion engine is run in a non-combustion state at the time of conducting the motoring test, the exhaust itself is present while the exhaust gas otherwise produced by the combustion is not, so that the exhaust should be treated.

The invention is not limited to an internal combustion engine which has cylinders arranged in a V shape and an internal combustion engine which has inline cylinders, but can be adapted to an internal combustion engine of any structure. The structure of the exhaust treatment apparatus is not limited to the illustrated structures of the individual embodiments, but may be embodied in other specific forms within the scope of the invention.