JPS6235885Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine in which an air cleaner and a pre-cleaner are disposed in an intake passage forming an intake system.

Traditionally, internal combustion engines, especially internal combustion engines installed in earthmoving vehicles, etc., have been used for example when working in tunnels, because dirt, small debris, etc. are scattered into the air during the work, so it is very difficult to use only a normal air cleaner. Air cleaners often become clogged early, and for this reason, devices equipped with a pre-cleaner separate from the air cleaner are used.

In an internal combustion engine equipped with this precleaner, the intake air supplied to the internal combustion engine can be sufficiently purified by the action of the precleaner and air cleaner, but dirt, etc. may accumulate in the dust pan of the precleaner. Therefore, when used for a long period of time, the function of this precleaner deteriorates and the air cleaner becomes clogged, and this clogging increases suction resistance, making it difficult to supply sufficient air to the internal combustion engine. The problem arises that it is not possible to

Therefore, the precleaner had to be cleaned after being operated for the required time.

In particular, when an earthmoving vehicle is used in a work environment (e.g. inside a tunnel) where the air contains many impurities (earth and sand, small debris, etc.), the function of the precleaner deteriorates quickly, and cleaning of the precleaner This has to be done after the precleaner has been operated for a short period of time, and therefore, cleaning of the precleaner is complicated and time is wasted.

Therefore, in order to prevent the function of the precleaner from deteriorating, a bypass passage is provided that communicates the precleaner with the exhaust system of the internal combustion engine, and a portion of the air inside the precleaner is sucked directly into the exhaust system by the action of exhaust gas. In addition, an internal combustion engine has been proposed in which impurities adhering to the dust pan of the precleaner are discharged into the exhaust system together with this air.

In an internal combustion engine having this bypass passage, a part of the intake air in the precleaner is mixed with impurities attached to the dust pan of the precleaner due to the action of exhaust gas during operation of the internal combustion engine, and the air is discharged from the bypass passage and the exhaust system. Since the precleaner is discharged to the outside through the passage, it is possible to prevent impurities from deteriorating the function of the precleaner, but a portion of the intake air that should be supplied to the internal combustion engine is wasted and exhausted to the outside through the exhaust system. Therefore, when high output is required, such as during actual operation of earthmoving vehicles, intake air cannot be supplied sufficiently and the back pressure of exhaust gas in the exhaust system increases, resulting in a decrease in intake efficiency and exhaust efficiency. There was a problem that the output of the internal combustion engine was reduced due to a decrease in the amount of fuel, and the exhaust gas concentration was also worsened.

The present invention was developed in view of the above-mentioned facts, and its purpose is to effectively discharge impurities that adhere to the dust pan of the precleaner to the outside, as well as to prevent output reduction and reduction during actual operation. An object of the present invention is to provide an improved internal combustion engine that can also prevent deterioration of exhaust gas concentration.

According to the present invention, an intake system including an intake passage, an air cleaner and a pre-cleaner disposed in the intake passage, an exhaust system including an exhaust passage and a muffler disposed in the exhaust passage, the pre-cleaner and the exhaust In an internal combustion engine equipped with a bypass passage that communicates with the system, the bypass passage is provided with an on-off valve member that can be selectively brought into an open state that opens the bypass passage and a closed state that closes the bypass passage. An internal combustion engine is provided.

Hereinafter, preferred embodiments of an internal combustion engine constructed according to the present invention will be described with reference to the accompanying drawings.

In FIG. 1, an internal combustion engine indicated by reference number 2 installed in, for example, an earthmoving vehicle has a
An intake pipe 4, an air cleaner 6, which constitute a downstream passage, an intake pipe 8, and a precleaner 10, which constitute an upstream intake passage, are connected to the upstream side in the direction in which intake air flows, and to the exhaust side thereof, In the direction in which exhaust gas flows, the upstream exhaust pipe 12, which constitutes the upstream exhaust passage 11 (see Figure 2), the muffler 14, and the downstream exhaust pipe 15, which constitutes the downstream exhaust passage 15 (see Figure 2), sequentially go downstream in the direction in which exhaust gas flows. A side exhaust pipe 16 is connected.

For example, this precleaner 10 removes impurities by centrifugal inertia of the intake air flow.
Separates into a dust pan section provided on the inner surface of the
It is generally known as an SU type precleaner.

The internal combustion engine 2 further includes a turbine (not shown) disposed in the upstream exhaust pipe 12 and rotated by exhaust gas, and a turbine (not shown) disposed in the intake pipe 4 and rotated integrally with the turbine. A turbocharger 18 consisting of a moving compressor (not shown) is installed.

Therefore, in the internal combustion engine 2 as described above, the intake pipe 4, the compressor (not shown), the air cleaner 6 in which a filter member (not shown) is disposed, the intake pipe 8, and the precleaner 10 are used. The upstream exhaust pipe 12,
A turbine (not shown), a muffler 14, and a downstream exhaust pipe 16 constitute an exhaust system.

The internal combustion engine 2 further includes a precleaner 1 at one end.
0 and whose other end is connected to the muffler 14 is provided. The pipe member 20 constitutes a bypass passage 22 (see FIG. 3) that bypasses the internal combustion engine 2 and directly communicates the inside of the precleaner 10 and the inside of the muffler 14 of the exhaust system.

Next, the muffler 14 will be explained with reference to FIG. 2. The muffler 14 includes a muffler main body 24.
Equipped with: One end of the upstream exhaust pipe 12 is connected to the muffler main body 24 , and an end having a plurality of holes 32 formed in its circumferential surface is disposed within the muffler main body 24 . Further, one end of the downstream exhaust pipe 16 is also connected to the muffler main body 24, and the end with a plurality of holes 34 formed on its circumferential surface is connected to the muffler main body 24.
It is located within 4.

Therefore, in the muffler 14, the exhaust gas discharged from the internal combustion engine 2 is passed through the upstream exhaust passage 11 of the upstream exhaust pipe 12, the holes 32 formed in the upstream exhaust pipe 12, and the downstream exhaust pipe 16. The gas is discharged to the outside through the hole 34 and the downstream exhaust passage 15 of the downstream exhaust pipe 16.

In the illustrated example, a throttle portion 36 is further formed inside the downstream exhaust pipe 16 located within the muffler body 24 at a position downstream of the hole 34 in the direction in which exhaust gas flows. ,and,
One end portion of the pipe member 20 that penetrates the end wall of the downstream exhaust pipe 16 and forms the bypass passage 22 is disposed in the constricted portion 36 . This constriction part 36 is provided to increase the flow rate of the exhaust gas so that the exhaust pressure of the exhaust gas in the constriction part 36 is lower than the intake pressure in the precleaner 10, and therefore,
When the exhaust gas flows through this throttle section 36, the air in the precleaner 10 described above is sucked out to the downstream exhaust passage 15 of the downstream exhaust pipe 16 via the bypass passage 22 due to the action of the exhaust gas.

The internal combustion engine 2 having the bypass passage 22 as described above is known, and therefore the internal combustion engine 2 has the bypass passage 22 as described above.
When the system is operated, a part of the intake air in the precleaner 10 passes through the bypass passage 22 to the downstream exhaust passage 15 along with impurities attached to the dust pan section (not shown) of the precleaner 10 due to the action of exhaust gas. The intake air is sucked out and exhausted to the outside through the downstream exhaust passage 15 along with the exhaust gas, but some of the intake air is directly exhausted to the outside through the exhaust system, so that it is not taken into the internal combustion engine. The problem arises that the amount of air flowing through the exhaust gas decreases, resulting in a decrease in output and a worsening of the exhaust gas concentration.

Therefore, the present invention is as shown in FIG.
The bypass passage 22 is characterized in that an opening/closing valve member 38 for opening and closing the passage 22 is disposed in the bypass passage 22 .

In the illustrated embodiment, the valve member 38 is comprised of a butterfly valve 40 . The butterfly valve 40 is fixed to a shaft member 42 that is rotatably attached to the pipe member 20. Therefore, by rotating the shaft member 42 from the outside, the butterfly valve 40 can be moved as shown by the solid line in FIG. It can be rotated between the closed position shown in FIG. 3 and the open position shown by the two-dot chain line 40A in FIG.

Although not shown, a lever member is fixed to one end of the shaft member 42, and an operating lever is provided at the driver's seat of the earthmoving vehicle, and the lever member and the operating lever are connected by a connecting member such as a wire. ing.
Therefore, when the driver manually operates the operating lever, the butterfly valve 40 is rotated via the connecting member and the lever member.

Next, the internal combustion engine 2 having the configuration as described above will be described.
The effects of this will be explained.

For example, when removing impurities in the precleaner 10 during inspection, etc., hold the control lever (not shown) by hand and move the butterfly valve 40 from the closed position shown by the solid line in FIG. position in the open position shown by the two-dot chain line. In this way, the bypass passage 22 is opened, and due to the action of the exhaust gas discharged from the internal combustion engine 2, a part of the intake air in the precleaner 10 passes through the bypass passage 22 with impurities in the precleaner 10 to the downstream side. Exhaust passage 1
5, and the exhaust gas is sucked out to the downstream exhaust passage 1 along with the exhaust gas.
5 and is discharged to the outside. In this way, impurities adhering to the inside of the precleaner 10 (the dust pan section) can be discharged to the outside through the exhaust system, thereby preventing a decline in the functionality of the precleaner.

After removing the impurities adhering to the inside of the precleaner 10, the operation lever (not shown) is operated to return the precleaner to its original state. Thus, butterfly valve 40
is the third position from the open position shown by the two-dot chain line 40A in FIG.
It is positioned in the closed position shown by the solid line in the figure, and the bypass passage 22 is closed. In this way, a part of the intake air in the precleaner 10 is prevented from being sucked out to the downstream exhaust passage 15 via the bypass passage 22, and the output of the internal combustion engine 2 and the exhaust gas concentration are reduced due to a decrease in intake efficiency and exhaust efficiency. deterioration can be prevented.

As can be easily understood from the above description, the present invention is particularly useful for internal combustion engines installed in earthmoving vehicles used in work environments where the air contains a large amount of impurities.

Although preferred specific examples of the internal combustion engine constructed according to the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such specific examples, and without departing from the scope of the present invention. Various modifications and modifications are possible.

For example, in the specific example, the butterfly valve is rotated by an operating lever disposed on the driver's seat, but in some cases, it may also be rotated by an electromagnetic solenoid or the like. In this case,
Connect the output end of the electromagnetic solenoid directly to a lever member fixed to one end of the shaft member, and energize the electromagnetic solenoid only when removing impurities in the precleaner (for example, by installing an operating switch in the driver's seat). ,
By closing this operating switch, the electromagnetic solenoid is energized) to position the butterfly valve in the open position.

In the above description, the butterfly valves are all opened and closed manually, but the butterfly valves can also be opened and closed automatically by detecting the state of the internal combustion engine.
In this case, for example, a temperature detector for detecting the temperature of the internal combustion engine is disposed in the internal combustion engine, a lever member is fixed to one end of the shaft member to which the butterfly valve is fixed, and the lever member The output end of an electromagnetic solenoid that is energized based on a signal from a temperature sensor is connected to The butterfly valve may be positioned in the open position by energizing the electromagnetic solenoid based on the signal.

[Brief explanation of the drawing]

1 is a schematic diagram illustrating a preferred embodiment of an internal combustion engine constructed in accordance with the present invention; FIG.
FIG. 3 is a partially omitted sectional view showing a muffler of the internal combustion engine shown in FIG. 1, and FIG. 3 is a partially omitted sectional view showing a part of the bypass passage of the internal combustion engine shown in FIG. 2... Internal combustion engine, 4... Intake pipe, 6... Air cleaner, 8... Intake pipe, 10... Precleaner,
11... Upstream exhaust passage, 14... Muffler, 15
...Downstream exhaust passage, 22...Bypass passage, 3
8...Valve member.

Claims (1)

[Claims for Utility Model Registration] 1. An intake system including an intake passage, an air cleaner and a pre-cleaner disposed in the intake passage; an exhaust system including an exhaust passage and a muffler disposed in the exhaust passage; In an internal combustion engine comprising a bypass passage communicating a cleaner and the exhaust system, the bypass passage includes an on-off valve member that is selectively brought into an open state for opening the bypass passage and a closed state for closing the bypass passage. An internal combustion engine characterized by: 2. The on-off valve member is constituted by a butterfly valve rotatably mounted between an open position for opening the bypass passage and a closed position for closing the bypass passage.Claim 1 of the Utility Model Registration Claim: The internal combustion engine described. 3. The internal combustion engine according to claim 1 or 2, wherein one end of the bypass passage is opened to a throttle portion provided in the muffler.