JP4683486B2 - Engine with breather device - Google Patents

Description

  The present invention relates to an engine with a breather device, and more particularly to an engine with a breather device suitable for suppressing moisture icing in a breather passage.

  In a small general-purpose engine used for an engine-driven generator or the like, a breather tube is routed outside the engine in order to allow blow-by gas to communicate with an intake passage. Therefore, in this type of engine, the breather tube is exposed to the outside air temperature, and in cold regions where the outside air temperature is extremely low, the moisture contained in the blow-by gas passing through the breather tube freezes to block the breather tube. It can happen.

As a countermeasure, for example, in the blow-by gas processing apparatus described in JP-A-8-246837, heat conduction is caused in a connection portion between the breather tube and the intake passage, which is a portion where the freezing is likely to occur in the blow-by gas passage. Attempts have also been made to provide an anti-icing pipe consisting of an inner wall portion made of a material having a low rate and easy to peel off attached ice.
JP-A-8-246837

  Even if the anti-icing pipe is formed of a material that easily peels ice as in the blow-by gas processing apparatus described in Patent Document 1, the ice is often not peeled off only by the momentum of the blow-by gas. In addition, when ice that has grown large is peeled off, the large ice may accumulate on the downstream side and block the pipeline.

  An object of the present invention is to solve the above-mentioned problems, make it difficult for ice to adhere to the tube wall, and even if it is temporarily attached, it can be peeled off at an early stage to prevent the ice from growing greatly. It is to provide an engine with a mark.

  To achieve the above object, the present invention provides an engine with a breather device that introduces blow-by gas into an intake passage of an engine through a blow-by gas passage of the engine through the blow-by gas passage. The first feature is that a movable member that is freely movable in the breather tube is accommodated in the breather tube that is an external passage portion.

  In the engine with a breather device for introducing blow-by gas into the intake passage of the engine via the blow-by gas passage, a part of the blow-by gas passage is placed in a breather tube that is an external passage portion of the engine. A second feature is that a movable member is provided that is fixed to the inner surface of the breather tube and that the remaining part is freely extended along the flow direction of the blow-by gas.

In addition, the present invention has a third feature in that the movable member is a coil spring,
The coil spring has a fourth feature in that the coil diameter is set larger than that of the other part so that the outer peripheral part thereof is in close contact with the inner surface of the breather tube in at least a part of the length direction.

  Furthermore, the present invention provides a resin material in which at least the inner surface of the breather tube has a low thermal conductivity and a high self-lubricity, such as nylon, fluororesin, acryl vinyl chloride, polycarbonate, polyethylene, and ABS resin. The fifth feature is that they are equal.

  According to the present invention having the first to fifth features, the movable member vibrates or moves in the breather tube due to engine vibration or breather pulsation, and comes into contact with the inner surface of the breather tube. It can prevent adhering to the inner wall.

  In particular, according to the first feature, the movable member can move not only in the breather tube but also in rotation and forward and backward in the breather tube. According to the second feature, the free part of the movable member vibrates in the breather tube.

  According to the present invention having the third feature, the outer periphery of the vibrating coil spring collides with the wall surface in the breather tube to prevent icing and to scrape off the ice.

  According to the present invention having the fourth feature, the coil spring can be held in the breather tube by its own elasticity, so that a complicated method and a fastening tool for fixing the coil spring are not used, and the configuration can be improved. Simplified.

  According to the present invention having the fifth feature, it is difficult to be affected by an external low temperature environment, so that it is difficult to freeze, and even if ice adheres, it can be easily peeled only by contacting the movable member. In particular, nylon, fluororesin, acryl vinyl chloride, polycarbonate, polyethylene, ABS resin, and the like have high self-lubricating properties, so that it is difficult for ice to adhere to them, and attachment to the inner wall of the breather tube and integral molding are easy.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 is a perspective view of an engine-driven generator driven by an engine with a breather device according to an embodiment of the present invention. The generator 1 includes an engine 4 and a generator main body 5 that are housed in the bottom of a space formed by a bottom plate 2 and a tube frame 3. A fuel tank 6 is provided above the engine 4 and the generator body 5, and an operation panel 7 is disposed behind the fuel tank 6. An air cleaner 8 and a muffler 9 are disposed adjacent to the engine 4. A breather tube 11 is provided between the head cover 10 of the engine 4 and the air cleaner 8 to connect the two. The breather tube 11 passes through a support portion (choke stay) of the choke assembly 12, and one end is inserted into a hole formed in the head cover 10, and the other end is drawn into the case of the air cleaner 8 to hook inside (not shown). ).

  FIG. 1 is a cross-sectional view of a breather tube exposed to an external environment in a blow-by gas passage. The breather tube 11 is expanded and fitted so that the end portion of the air cleaner 8 is fitted to the outer periphery of the blow-by gas receiving port 8A formed in the air cleaner 8. A spring (compression coil spring in this example) 13 is disposed in the breather tube 11. The spring 13 may be extended over the entire length of the breather tube 11 (distance from the head cover 10 to the air cleaner 8), or the portion where the blow-by gas may freeze in a low-temperature environment, that is, the air cleaner 8 receiving the blow-by gas. It may be provided only corresponding to the vicinity of the inlet 8A.

  For example, the spring 13 may be provided from an intermediate portion of the breather tube 11 to an overlapping region between the breather tube 11 and the receiving port 8A. Here, the outer diameter of the spring 13 is set to be tight, that is, slightly larger than the inner diameter of the breather tube 11 at the end portion (winding start portion) 13A on the engine 4 side. Except for the end portion 13A, the outer diameter of the spring 13 is set smaller than the inner diameter of the breather tube 11, and the spring 13 is configured to be displaceable in the radial direction of the breather tube 11 in the breather tube 11. . With such a setting, the spring 13 inserted into the breather tube 11 is fixed to the inner wall of the breather tube 11 only by the end portion 13 </ b> A, and the other portions can freely vibrate within the breather tube 11.

  Therefore, when the engine 4 is operated and blow-by gas flows into the air cleaner 8 from the engine 4, the spring 13 vibrates due to the gas flow and the vibration of the engine 4. In particular, the spring 13 is struck against the inner wall of the receiving port 8A when the spring 13 vibrates in the receiving port 8A where moisture in the blow-by gas is likely to freeze, so that freezing is prevented. Even if ice adheres to the inner wall of the receiving port 8A, it can be peeled off before the ice grows large.

  In the example of FIG. 1, the arrangement and the fixed position of the spring 13 are set so as to be suitable for preventing the ice from adhering to the blow-by gas inlet 8A of the air cleaner 8, but the position where the ice is not desired to be attached is set. In particular, the length of the spring 13 and the fixed position can be arbitrarily set so as to match the position.

  FIG. 3 is a schematic view of the breather tube portion showing a modification of the spring 13 with the fixed position and length changed. FIG. 3A shows an example in which the spring 13 is fixed in the breather tube 11 by increasing the outer diameter at the central portion 13 </ b> B of the spring 13. In this example, the spring 13 greatly vibrates at a portion where both ends of the spring 13 are located, and ice adhesion at this portion can be prevented.

  FIG. 3B shows an example in which the outer diameter is increased at both ends 13 </ b> C and 13 </ b> D of the spring 13 and the spring 13 is fixed in the breather tube 11. In this example, the spring 13 vibrates at a position where the middle portion of the spring 13 is located, and it is possible to prevent the ice from adhering to this position.

  FIG. 4 is a cross-sectional view of the connecting portion between the breather tube and the air cleaner according to the second embodiment. In the example shown in FIG. 4, the breather tube 11 is connected to the blow-by gas receiving port 8 </ b> A of the air cleaner 8 in the immediate vicinity of the bent portion R of the breather tube 11. The spring 13 extends in a range including the bent portion R, and an end portion having an enlarged outer diameter, that is, a winding start portion 13A is in close contact with the inner wall of the breather tube 11 at an intermediate portion of the breather tube 11. It is fixed. In this example, the spring 13 can vibrate at the free end accommodated in the receiving port 8A. Since the spring 13 contacts the inner surface of the bent portion R in the portion of the spring 13 located at the bent portion R, vibration is suppressed. However, the spring 13 can vibrate between the bent portion R and the winding start portion 13A.

  Thus, also in the region including the bent portion R as in the second embodiment, the spring 13 can be applied to the blow-by gas passage utilizing its flexibility.

  The breather tube 11 and the inlet 8A of the air cleaner 8 are made of a resin material having low thermal conductivity and high self-lubricating properties such as nylon, fluororesin, acrylic, vinyl chloride, polycarbonate, polyethylene, ABS resin. Is desirable. Moreover, it is not necessary for the whole to be such a resin material, and at least an inner surface portion in which a free portion of the spring 13 that is not restrained vibrates and collides may be formed of nylon or the like. This is because it is difficult for the ice to adhere and the ice attached by the collision of the spring 13 is easily peeled off. A resin material such as nylon is formed by coating or sticking to at least the inner surface of the breather tube 11 or the like, or by integrally molding with the breather tube 11 or the like.

  The spring 13 is not limited to increasing the outer diameter of the winding start portion 13 </ b> A and closely contacting the inner surface of the breather tube 11. FIG. 5 is a cross-sectional view of a breather tube showing a modification of the fixing method of the spring 13. In this modification, the outer diameter of the spring 13 is set smaller than the inner diameter of the breather tube 11 over the entire length. Preferably, the outer diameter is smaller than the inner diameter of the breather tube 11 and is uniform. In this way, a band or a grip is used as the fastener 14 in order to hold the spring 13 having a small outer diameter on the breather tube 11. That is, the breather tube 11 itself is made of a flexible material that can be compressed (nylon or the like). Therefore, the breather tube 11 is tightened from the outer periphery with a fastener 14, the inner surface of the breather tube 11 and the spring 13. And make it close. The structure and type of the fastener 14 are arbitrary, but a general-purpose gas hose band, tube clip, or the like is suitable.

  As described above, in the present embodiment, it is prevented that the breather tube 11 or the breather tube 11 and the connection portion between the air cleaner 8 are frozen due to the vibration of the spring, and even if the ice is frozen, it is beaten before the ice grows greatly. Can be dropped. Further, the length, wire diameter, outer diameter and other sizes and materials of the spring 13 are determined so that the natural frequency of the spring 13 matches the rotational speed of the engine 4 so that the effect of vibration of the spring 13 can be maximized. It is desirable to make it.

  Although the present invention has been described according to the best mode, the present invention is not limited to this embodiment and can be variously modified. For example, instead of the compression coil spring 13, a long foil or thin plate vibrating piece is arranged such that an arbitrary part thereof is fixed in the breather tube 11 and the other part is displaceable. For example, one end is fixed and the other end is extended in the downstream direction of the gas flow so as to be blown. The blown-off foil or thin plate vibrates in the same manner as the spring 13 due to the blow-by gas flow or the vibration of the engine, and can achieve an anti-icing effect. In addition, since the vibration piece of foil or a thin plate gives a random motion by providing unevenness by bending or embossing, it can prevent freezing in a wide range.

  Further, instead of fixing a part of the spring 13 in the breather tube 11, the spring 13 may be freely movable in the breather tube 11. In this case, in order to limit the moving range of the spring 13 in the pipe line direction of the breather tube 11, it is preferable to provide a rib or the like along the inner wall of the breather tube 11 to partially reduce the inner diameter.

It is side surface sectional drawing of the breather tube which accommodated the coil spring which concerns on one Embodiment of this invention. It is a perspective view of an engine drive type generator with a breather device concerning one embodiment of the present invention. It is side surface sectional drawing of the breather tube which shows the modification of the attachment aspect of a coil spring. It is sectional drawing of the connection part of the breather tube and air cleaner which concern on 2nd Embodiment of this invention. It is side surface sectional drawing of the breather tube which shows the 2nd modification of the attachment aspect of a coil spring.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine drive type generator, 4 ... Engine, 5 ... Generator main body, 8 ... Air cleaner, 10 ... Head cover, 11 ... Breather tube, 13 ... Coil spring, 14 ... Fastener

Claims (7)

In an engine with a breather device that introduces blow-by gas into the intake passage of the engine via the blow-by gas passage,
Of the blow-by gas passage, a movable member extending along a flow direction of blow-by gas in a breather tube that is an external passage portion of the engine, a part of which is fixed to the inner surface of the breather tube, and the remaining portion A breather-equipped engine comprising a movable member configured to be freely displaceable in a radial direction of the breather tube . It said movable member, the breather device with engine according to claim 1, characterized in that the coil spring. The breather device according to claim 2 , wherein the coil spring has a coil diameter larger than that of the remaining portion so that an outer peripheral portion thereof is in close contact with the inner surface of the breather tube in at least a portion of the length direction. With engine. The engine with a breather device according to claim 1 , wherein the movable member is a long foil extending along a flow direction of blow-by gas in the breather tube . It said movable member is in the breather tube, the breather device with engine according to claim 1, wherein the along the flow direction of the blow-by gas is a thin elongated were extended. The engine with a breather device according to any one of claims 1 to 5, wherein at least a portion constituting the inner surface of the breather tube is made of a resin material having low thermal conductivity and high self-lubricity . The engine with a breather device according to claim 6, wherein the resin material is any one of nylon, fluororesin, acrylic vinyl chloride, polycarbonate, polyethylene, and ABS resin.

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