JP2008223657A - Free-piston engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent or suppress the deterioration of power generation efficiency caused by an influence of high heat in the vicinity of an exhaust port when one combustion chamber is formed between two pistons. <P>SOLUTION: One combustion chamber 51 is formed between a pair of pistons 41, 42 slidably fitted in of a cylinder 30, and the pair of pistons 41, 42 is driven in a direction where they are separated from each other by receiving combustion pressure in the combustion chamber 51. An intake port 71 and the exhaust port 61 which are opened in the combustion chamber 51 are positioned with a space in a cylinder axis direction. In the cylinder axis direction, the exhaust port 61 is positioned in a position close to one piston 41 and in a position far from the other piston 42. A first generator 81 for generating electricity by reciprocating one piston 41 and a second generator 91 for generating electricity by reciprocating the other piston 42 are arranged in a position nearer to the other piston 42 than the exhaust port 61 in the cylinder axis direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a free piston engine.

  Recently, a free piston engine has attracted attention from the viewpoint of efficiently extracting thermal energy of combustion gas. Patent Document 1 discloses a technique in which a permanent magnet provided on a piston of a free piston engine generates power by reciprocating in a magnetic field of a linear generator. Patent Document 2 proposes a free piston engine in which one combustion chamber is formed between two pistons fitted in a cylinder, and the two pistons are driven in the separation direction by the combustion pressure in the combustion chamber. Has been. In the free piston engine of the type described in Patent Document 2, the movement directions of the two pistons arranged in one cylinder are opposite to each other, and therefore it is particularly preferable in terms of vibration reduction. The

In the above-mentioned Patent Document 2, an exhaust port and an intake port that are opened in the combustion chamber are arranged apart from each other in the cylinder axial direction, that is, the exhaust port is close to one piston in the cylinder axial direction. In addition, it has been proposed to be disposed at a position far from the other piston. Further, in Patent Document 2, a first generator that generates power with the one piston is disposed on the opposite side of the other piston from one piston, and a second generator that generates power with the other piston. There has also been proposed a structure in which a generator is arranged on the opposite side of one piston with the other piston as a boundary.
JP 2005-155345 A JP 2005-155345 A

  By the way, when generating electric power in a free piston engine, power generation efficiency will fall if a generator receives high heat. In the free piston engine, the vicinity of the exhaust port is hotter than the other parts, so the members near the exhaust port are easily affected by the high heat. From this point of view, considering the arrangement position of the two generators as described in Patent Document 2 from the positional relationship with respect to the exhaust port, the first generator driven by one piston is in the cylinder axial direction. , The power generation efficiency of the first generator is easily influenced by the high heat in the vicinity of the exhaust port, as compared with the second generator driven by the other piston. This will cause a decrease in power generation efficiency.

  The present invention has been made in view of the above circumstances, and its purpose is to reduce the power generation efficiency due to the influence of high heat near the exhaust port when one combustion chamber is formed between two pistons. An object of the present invention is to provide a free piston engine that prevents or suppresses the above.

In order to achieve the above object, the following solution is adopted in the present invention. That is, as described in claim 1 in the claims,
A combustion chamber is formed between a pair of pistons slidably fitted in the cylinder, and the pair of pistons are driven in directions away from each other by receiving the combustion pressure in the combustion chamber. In the free piston engine
By setting the intake port and the exhaust port that are opened in the combustion chamber to be separated from each other in the cylinder axial direction, the exhaust port is close to one of the pair of pistons in the cylinder axial direction. Is located at a position farther than the other piston,
A first generator that generates electricity by reciprocating the one piston, and a second generator that generates electricity by reciprocating the other piston,
Each of the generators is disposed in a position closer to the other piston than the exhaust port in the cylinder axis direction.
It is like that.

  According to the above solution, the first generator is driven by one piston to generate power, and the other generator is driven by the other piston to generate power. Each generator is disposed in the cylinder axis direction at a position closer to the other piston than the exhaust port, that is, each generator is disposed at a position far from the exhaust port. Therefore, each generator is prevented from being affected by high heat in the vicinity of the exhaust port, or the degree of influence from high heat is reduced, which is preferable for preventing reduction in power generation efficiency due to high heat. Further, the length in the cylinder axial direction can be suppressed as compared with the case where each generator and each piston are arranged in series in the cylinder axial direction.

A preferred mode based on the above solution is as described in claim 2 and the following claims. That is,
Each of the generators is arranged at a position opposite to the exhaust port with the other piston as a boundary in the cylinder axial direction (corresponding to claim 2). In this case, the position of each generator can be set sufficiently far from the exhaust port, which is even more preferable in preventing the reduction in power generation efficiency.

The first generator includes a first permanent magnet held by a first magnet holder that is displaced according to the reciprocation of the one piston, and a first power generator disposed in the vicinity of the first permanent magnet. Coil for
The second generator includes a second permanent magnet held by a second magnet holder that is displaced according to the reciprocating motion of the other piston, and a second power generator disposed in the vicinity of the second permanent magnet. Coil for
The first magnet holder is disposed at a position opposite to the exhaust port with the other piston as a boundary in a cylinder axial direction;
The first magnet holder is connected to the one piston via a connecting member extending along the cylinder;
(Corresponding to claim 3). In this case, each generator, particularly the first generator that is easily affected by high heat from the exhaust port, is disposed at a position far away from the exhaust port by a simple structure of providing a connecting member extending along the cylinder. can do.

  The connecting member is arranged on the opposite side in the radial direction of the cylinder with respect to an exhaust passage extending from the cylinder and connected to the exhaust port (corresponding to claim 4). In this case, it is preferable to dispose the connecting member at a position where the influence of the high heat of the exhaust passage is as difficult as possible to prevent the high heat from being transmitted to the first generator via the connecting member. Become.

Each of the generators is a linear generator that generates electricity by reciprocating the permanent magnet with respect to the power generation coil as the piston reciprocates.
The casing of the first generator and the casing of the second generator are constituted by one common casing,
Each power generating coil, each magnet holder and each permanent magnet are disposed in the common casing,
Each of the power generating coils is fixed to the common casing,
(Corresponding to claim 5). In this case, the casings of the respective generators are configured by a single common casing, which is preferable for a compact configuration as a whole, and also preferable for cost reduction and the like. In addition, the force acting between the first permanent magnet and the first power generating coil is offset by the force acting between the second permanent magnet and the second power generating coil, and a specific force is applied to the casing. This is also preferable in preventing a large force from acting only in one direction.

A plurality of the first power generation coils are provided at intervals in the circumferential direction of the common casing, and the first magnet holding body and the first permanent magnet correspond to the plurality of first power generation coils, respectively. A plurality of common casings are provided at intervals in the circumferential direction.
A plurality of the second power generation coils are provided at intervals in the circumferential direction of the common casing, and the second magnet holding body and the second permanent magnet correspond to the plurality of second power generation coils, respectively. A plurality of common casings are provided at intervals in the circumferential direction.
The first power generation coil and the second power generation coil are alternately arranged in the circumferential direction of the common casing,
The first magnet holder and the second magnet holder are alternately arranged in the circumferential direction of the common casing,
The first permanent magnet and the second permanent magnet are alternately arranged in the circumferential direction of the common casing,
(Corresponding to claim 6). In this case, by disposing the members constituting each generator alternately at intervals in the circumferential direction of the casing, an excessive bending force is applied to each piston and each cylinder that receives the reaction force accompanying power generation. This is preferable in preventing the action. In addition, by disposing each component of each generator in the circumferential direction of the casing, it is preferable to secure a large power generation capacity while shortening the length of the casing.

  According to the present invention, it is possible to prevent or suppress a decrease in power generation efficiency due to the influence of high heat near the exhaust port.

  FIG. 1 shows an embodiment in which a free piston engine is used for supplying power to a motor that drives an automobile as a vehicle. In FIG. 1, reference numeral 1 denotes a driving (running) motor, which is an AC motor in the embodiment. Reference numerals 2R and 2L denote left and right driving wheels (front wheels or rear wheels). The driving wheels 2R and 2L are driven by the motor 1 via the differential gear 3.

  Reference numeral 10 denotes a free piston engine. The free piston engine 10 is configured as a unit body including an engine body 11 including a piston and a cylinder and a generator 81.91 described later. The engine body 11 drives the generators 81 and 91, and the electric power (alternating current) generated by the generators 81 and 91 is converted into direct current by the rectifier 20, and then the motor via the DC-AC converter 21. 1, surplus power is supplied to the battery 22. In addition, power from the battery 22 is supplied to the motor 1 via the DC-AC converter 21. In order to recover regenerative energy during braking, the electric power generated by the motor 1 is converted into direct current by the rectifier 23 and then boosted by the DC-DC converter 24 and supplied to the battery 22 during braking.

The flow of power supply according to the driving state of the automobile is performed, for example, as follows, and the maximum power generation amount by the free piston engine 10 is sufficiently large to ensure the maximum output by the motor 1. .
(1) When the required power generation amount is very small At the time of starting or at an extremely light load, and when the storage amount of the battery 22 is large. At this time, the generators 81 and 91 do not generate power (the free piston engine 10, that is, the engine main body 11 is stopped), and power is supplied only from the battery 22 to the motor 1.
(2) When the required power generation amount is small It is when the battery 22 has a large amount of stored power during light load to medium load. At this time, power is generated by the generators 81 and 91 (the free piston engine 10 is operated), and electric power is supplied exclusively from the generators 81 and 91 to the motor 1 (a little surplus power is generated to generate power). The surplus power may be stored in the battery 22).
(3) When the required power generation amount is medium to large When the power storage amount of the battery 22 is small during light load to high load. At this time, the generators 81 and 91 generate sufficient electric power more than necessary for traveling (the free piston engine 10 is operated), and the electric power is supplied from the generators 81 and 91 to the motor 1. Excess electric power is stored in the battery 22.
(4) Regenerative braking When the motor 1 functions as a generator driven by the drive wheels 2R, 2L. At this time, the electric power generated by the motor 1 is stored in the battery 22. In addition, although the free piston engine 10 may be stopped, the operation can be continued at an extremely low speed in preparation for the next power generation.

  Next, an example of the free piston engine 10 will be described with reference to FIG. In FIG. 2, the engine body 11 has a cylinder 30 constituted by a cylindrical member whose both ends are closed. A first piston 41 and a second piston 42 are slidably fitted in the cylinder 30. The pistons 41 and 42 are arranged in series and face each other. One combustion chamber 51 is formed in the space between the pistons 41 and 42 in the cylinder 30. Thereby, when receiving each combustion pressure in the combustion chamber 51, each piston 41, 42 is driven in a direction away from each other. The return force in the direction of compressing the combustion chamber 51 (direction approaching each other) can be applied to each piston 41, 42 by a return spring (not shown).

  In the embodiment, the engine body 11 is a self-ignition type two-cycle engine, and a cycle of compression, expansion, exhaust, and scavenging (intake) is repeated. For this reason, the exhaust port 61 is opened to the combustion chamber 51 and the intake port 71 is opened. A plurality of exhaust ports 61 are provided at intervals in the circumferential direction of the cylinder member 30, and each exhaust port 61 is connected to one exhaust passage 62. Similarly, a plurality of intake ports 71 are provided at intervals in the circumferential direction of the cylinder member 30, and each intake port 71 is connected to one intake passage 72.

  The exhaust port 61 and the intake port 71 are arranged at an interval in the cylinder axis direction (left-right direction in FIG. 2). More specifically, the exhaust port 61 is positioned near the first piston 41 serving as one of the pistons in the cylinder axis direction, and is positioned far from the second piston 42 serving as the other piston. Has been. In other words, the exhaust port 61 is set on the first piston 41 side with the axial center position of the cylinder 30 as a boundary. Conversely, the intake port 71 is positioned at a position far from the first piston 41 and at a position close to the second piston 42 in the cylinder axis direction. The exhaust passage 62 and the intake passage 72 are connected to the cylinder member 30 from one radial side of the cylinder member 30 and extend downward in FIG.

  In view of the setting of the arrangement positions of the exhaust port 61 and the exhaust passage 62 described above, the first piston 41 is likely to be hotter than the second piston 42, and in the circumferential direction of the cylinder member 30, in the vicinity of the exhaust passage 62. In addition, the lower side of FIG. 2, which is the direction in which the exhaust passage 62 extends, is likely to become hot.

  A first generator 81 and a second generator 91 are disposed outside the cylinder 30 on one end side in the cylinder axial direction. The first generator 81 is driven by the first piston 41, is fixedly arranged and extends long in the cylinder axial direction, and the first generator coil 82 extends long along the first power generation coil 82. A magnet holder 83 and a large number of first permanent magnets 84 fixedly held by the first magnet holder 83 are provided. The first power generation coil 82 is for three-phase alternating current, and the first permanent magnet 84 has N poles and S poles arranged alternately. As a result, the magnetic field is changed by reciprocating the first magnet holder 83, that is, the first permanent magnet 84 in the cylinder axial direction in a state where the magnetic field is generated in the first power generation coil 82, and the first magnetic coil is changed. Power generation by the generator 81 is performed. Thus, in the embodiment, the first generator 81 is a linear generator.

  In order to drive the first generator 81, an extension rod 41a extending slidably through one end portion (right end portion in FIG. 2) of the cylinder 30 is extended from the first piston 41. . The extending direction of the extension rod 41a is opposite to the second piston 42 with the first piston 41 as a boundary. The distal end portion of the extending rod 41 a and the first magnet holder 83 are connected by a connecting member 85. The connecting member 85 includes a first portion 85a and a second portion 85b that are integral with each other. The first portion 85 a is located on the extension line of the 21st magnet holder 83 and extends in the cylinder axial direction along the cylinder 30. The second portion 85b extends in the radial direction of the cylinder 30 and is integrated with the extension rod 41a. The first portion 85 a is set at a position that is 180 degrees opposite to the exhaust passage 62 in the radial direction of the cylinder 30. In addition, the casing 86 of the 1st generator 81 is shown with the dashed-dotted line in FIG.

  The second generator 91 is driven by the second piston 42, is fixedly arranged and extends long in the cylinder axis direction, and a magnet holder 93 extends long along the power generation coil 92. And a large number of permanent magnets 94 fixedly held by the magnet holder 93. The power generating coil 92 is for three-phase alternating current, and the permanent magnet 94 has N poles and S poles arranged alternately. Thus, the second generator 91 generates power by reciprocating the magnet holder 93, that is, the permanent magnet 94 in the cylinder axial direction in a state where a magnetic field is generated in the power generation coil 92. Thus, in the embodiment, the second generator 91 is a linear generator.

  In order to drive the second generator 91, an extension rod 42 a extending slidably through the other end portion (left end portion in FIG. 2) of the cylinder 30 is extended from the second piston 42. Yes. The extending direction of the extension rod 42a is opposite to the first piston 41 with the second piston 42 as a boundary. And the 2nd magnet holding body 93 is located on the extension line of this extension rod 42a, and the 2nd magnet holding body 93 is connected with the front-end | tip part of the extension rod 42a. In addition, the casing 96 of the 2nd generator 92 is shown with the dashed-dotted line in FIG.

  Here, the operation of the configuration shown in FIG. 1 will be described. First, when combustion is performed in the combustion chamber 51, the two pistons 41 and 42 receiving the combustion pressure are driven in a direction away from each other (driving toward the bottom dead center), and at this time, the first magnet holder 83 is driven. 2 is driven rightward in FIG. 2, while the second magnet holder 93 is displaced leftward in FIG. 2 to generate electricity. After the pistons 41 and 42 reach the bottom dead center, the combustion chamber 51 is displaced by a return spring (not shown) to prepare for the next combustion. By such reciprocation of the pistons 41 and 42, the vertical directions 83 and 93 (permanent magnets 84 and 94) are reciprocated at each time, and power generation is continuously performed.

  Here, each of the generators 81 and 91 is arranged at a position opposite to the exhaust port 61 with respect to the second piston 42, that is, a position that is not easily affected by the high heat of the exhaust port 61 or the exhaust passage 62. Therefore, the situation of a decrease in power generation efficiency due to high heat is prevented or suppressed. Moreover, since the 1st part 85a extended long along the cylinder 30 among the connection members 85 is located in the radial direction opposite side of the cylinder 30 with respect to the exhaust passage 62 used as high heat | fever, the 1st part 85a is high heat | fever. Is prevented or suppressed. In other words, the situation where high heat near the exhaust port 61 is transmitted to the first magnet holder 83 and the first permanent magnet 84 via the connecting member 85 is prevented or suppressed, which is more preferable for preventing or suppressing a decrease in power generation efficiency. It has become a thing. Furthermore, since the first generator 81 is conventionally disposed on the opposite side of the second piston 42 from the first piston 41 in the cylinder axial direction, that is, on the right side of the cylinder 30 in FIG. The overall length of the engine in the cylinder axial direction has become extremely long, but in the present invention, this length in the axial direction of the cylinder is greatly shortened.

  3 to 6 show a second embodiment of the present invention, and the same components as those in the above embodiment are given the same reference numerals, and redundant description thereof is omitted (this is described below) The same applies to the third embodiment). In the present embodiment, the casing of the first generator 81 and the second generator 91 is constituted by one common casing 97. Further, the constituent members 82 to 84 and 92 to 94 of the generators 81 and 91 are divided into a plurality of parts in the circumferential direction of the common casing 97.

  First, in FIG. 3, the common casing 97 has a circular inner hole 97a and is generally cylindrical, and one end thereof is closed (bottomed) and the other end is opened (see FIG. 3). 3 shows the opening side end of the common casing 97). The center (axis line) of the common casing 97 is set so as to be located on the extension line of the cylinder axis.

  Three first power generating coils 82 are fixed to the inner surface of the common casing 97 at equal intervals in the circumferential direction of the common casing 97. Three first magnet holders 83 and three first permanent magnets 84 are provided corresponding to the first power generating coil 82. Of course, the first magnet holder 83 and the first permanent magnets 84 fixed to the first magnet holder 83 are arranged at equal intervals in the circumferential direction of the common casing 97 while facing the first power generation coil 82.

  The second generator 91 is configured similarly to the first generator 81. That is, three second power generating coils 92 are fixed to the inner surface of the common casing 97 at equal intervals in the circumferential direction of the common casing 97. Three second magnet holders 93 and three second permanent magnets 94 are also provided corresponding to the second power generating coil 92. Of course, the second magnet holder 93 and the second permanent magnet 94 fixed to the second magnet holder 93 are arranged at equal intervals in the circumferential direction of the common casing 97 while facing the second power generation coil 92. The first power generation coil 82 and the second power generation coil 92 are alternately arranged in the circumferential direction of the common casing 97, and similarly, the first magnet holding body 83 and the second magnet holding body 93 are the common casing 97. The first permanent magnets 84 and the second permanent magnets 94 are alternately arranged in the circumferential direction of the common casing 97.

  An example of the connection mode between the first magnet holder 83 and the first piston 41 is shown in FIG. In FIG. 4, a connecting member 87 (corresponding to the connecting member 85 in the embodiment) is connected to the extension rod 41 a of the first piston 41. The connecting member 87 includes three first portions 87a (corresponding to the first portion 85a in the embodiment) arranged at equal intervals around the cylinder axis, and a substantially circular shape fixed to the extension rod 41a of the first piston 41. It has a plate-like second portion 87b (corresponding to the second portion 85b in the embodiment). The first portion 87a extends in the cylinder axial direction so as to surround the cylinder 30, and a first magnet holding body 83 is integrated at each tip portion thereof (integral molding may be performed, or a magnet as a separate member) The holding body 83 may be fixed to the first portion 87a with a fixing tool or the like). And the base end part of each 1st part 87a is integrated with respect to the outer-periphery edge part of the 2nd part 87b (in embodiment, each part 87a and 87b is integrally molded).

  An example of the connection mode between the second magnet holder 93 and the second piston 42 is shown in FIG. In FIG. 5, the second magnet holding body 93 has three divided structures arranged at equal intervals around the cylinder axis, and the base end portion thereof is integrated with the flange portion 93a. And it is being fixed to the extension rod 42a of the 2nd piston 42 in the flange part 93a part. The three magnet holders 93 are integrally formed with the flange portion 93a. Of course, the three second magnet holders 93 are arranged so as not to interfere with the three first magnet holders 83 and the first portion 87a of the connecting member 87 including the flange portion 93a (FIG. 3, FIG. (See FIG. 6).

  In the present embodiment, the casings of the two generators 81 and 91 are constituted by a single common casing 97, which is preferable for achieving compactness. Further, since the constituent elements 82 to 84 and 92 to 94 of the generators 81 and 91 are distributed in the circumferential direction of the common casing 97, a high power generation capacity can be obtained while shortening the overall length of the common casing 97. . Further, the reaction force applied to the common casing 97 during power generation (this reaction force is also transmitted to the pistons 41 and 42 and the cylinder 30) acts as a bending force on the cylinder axis as much as possible. However, it is preferable.

  7 to 9 show a third embodiment of the present invention. In this embodiment, two sets of engine main bodies 11 as shown in FIG. 2 are provided in an array, and the pistons 41 and 42 of the other set of engine main bodies are compressed using the combustion pressure in one set of engine main bodies. In this case, the return spring for returning the pistons 41 and 42 in the compression direction is unnecessary.

  First, the first engine main body is indicated by reference numeral 11X (corresponding to the engine main body 11 in FIG. 2), and the constituent elements of the first engine main body 11X are indicated by the reference numerals used in the first embodiment. It is shown with the sign “X”. Similarly, the second engine main body is indicated by reference numeral 11Y (corresponding to the engine main body 11 in FIG. 2), and the components of the second engine main body 11Y are the same as those used in the first embodiment. It is shown with the sign “Y”. 7 to 9, the cylinder 30 is not shown for the sake of simplification and clearly showing the coupling mode of each piston.

  In FIG. 7, the first piston 41 </ b> X (extension rod) of the first engine body 11 </ b> X and the second piston 42 </ b> Y (extension rod) of the second engine body 11 </ b> Y are connected by the first interlocking member 101. ing. Similarly, the second piston 42X (extension rod) of the first engine body 11X and the first piston 41Y (extension rod) of the second engine body 11Y are connected by the second interlocking member 102. Yes. Thus, the pistons 41Y and 42Y of the second engine body 11Y are driven so as to return to the compression direction (top dead center direction) by the combustion pressure of the first engine body 11X. Similarly, the pistons 41X and 42X of the first engine body 11X are driven so as to return to the compression direction (top dead center direction) by the combustion pressure of the second engine body 11Y.

  FIG. 8 shows details of the first interlocking member 101. FIG. 9 shows details of the second interlocking member 102. Each interlocking member 101, 102 is disposed between the engine bodies 11X and 11Y. The first interlocking member 101 transmits a force for interlocking in order to prevent (suppress) as much as possible an external force at the time of interlocking acting as a large bending force on the cylinder axis with respect to each engine body 11X, 11Y. As a member, it has a pair of upper and lower members 101a and 101b (in the embodiment, 101a is rod-shaped and 101b is plate-shaped).

  Similarly, the 21st interlocking member 102 is a force for interlocking in order to prevent (suppress) as much as possible the external force upon interlocking from acting as a large bending force on the cylinder axis with respect to each engine body 11X, 11Y. As a member for transmitting the signal, a pair of upper and lower members 102a and 102b are provided (in the embodiment, 102a is rod-shaped and 102b is plate-shaped). Each interlocking member 101 and 102 is configured not to interfere with each other when assembly is completed.

  Although the embodiment has been described above, the present invention is not limited to the embodiment, and can be appropriately changed within the scope described in the scope of claims. For example, the invention includes the following cases. . As the engine main body, the number of engine main bodies 11 can be appropriately selected according to the required power generation capacity, for example, by arranging three stages of the structure shown in FIG. 2 in parallel.

  The permanent magnets 84 and 94 are not provided integrally with the piston 41 or 42, for example, by providing a magnet holder linked to the piston 41 or 42 via a gear or the like. The permanent magnets 84 and 94 may be held in the magnet. In particular, when the permanent magnets 84 and 94 are interlocked with the piston 41.42 via gears, the permanent magnets 84 and 94 (magnet holders 83 and 93) are rotated forward and backward according to the reciprocation of the piston. In this case, as the generator 81.91, a rotary type having higher power generation efficiency can be used. The specification range of the free piston engine is not limited, such as being used not only for automobiles but also for stationary power generation. The free piston engine may be a spark ignition type or may adopt an appropriate type such as a four-cycle type. Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage.

The whole system diagram which shows embodiment at the time of utilizing a free piston engine for the electric power feeding to the motor for driving | running | working a motor vehicle. The 1st Embodiment of this invention is shown, and the partial cross section top view which shows an example of a free piston engine. The perspective view which shows 2nd Embodiment of this invention and shows an example at the time of making the casing of a 1st generator and a 2nd generator into one common casing. The perspective view which shows the connection aspect of the 1st piston and 1st magnet holding body which are used for 2nd Embodiment. The perspective view which shows the connection aspect of the 2nd piston used for 2nd Embodiment, and a 2nd magnet holding body. The figure which shows the connection aspect shown in FIG. 4 with the positional relationship with a 2nd magnet holding body, and is seen from a cylinder axial direction. The principal part top view which shows the 3rd Embodiment of this invention. The perspective view which shows the detail of the 1st interlocking member shown in FIG. The perspective view which shows the detail of the 2nd interlocking member shown in FIG.

DESCRIPTION OF SYMBOLS 10: Free piston engine 11: Engine main body 22: Battery 30 cylinders 41: 1st piston 42: 2nd piston 51: Combustion chamber 61: Exhaust port 62: Exhaust passage 71: Intake port 81: 1st generator 82: 1st Coil for power generation 83: First magnet holder 84: First permanent magnet 85: Connecting member 91: Second generator 92: Second generator coil 93: Second magnet holder 94: Second permanent magnet 87: Connecting member (Fig. 4)

Claims (6)

A combustion chamber is formed between a pair of pistons slidably fitted in the cylinder, and the pair of pistons are driven in directions away from each other by receiving the combustion pressure in the combustion chamber. In the free piston engine
By setting the intake port and the exhaust port that are opened in the combustion chamber to be separated from each other in the cylinder axial direction, the exhaust port is close to one of the pair of pistons in the cylinder axial direction. Is located at a position farther than the other piston,
A first generator that generates electricity by reciprocating the one piston, and a second generator that generates electricity by reciprocating the other piston,
Each of the generators is disposed in a position closer to the other piston than the exhaust port in the cylinder axis direction.
This is a free piston engine. In claim 1,
Each said generator is arrange | positioned in the cylinder axial direction in the position which becomes the other side to the said exhaust port on the other piston as a boundary, The free piston engine characterized by the above-mentioned. In claim 2,
The first generator includes a first permanent magnet held by a first magnet holder that is displaced according to the reciprocation of the one piston, and a first power generator disposed in the vicinity of the first permanent magnet. Coil for
The second generator includes a second permanent magnet held by a second magnet holder that is displaced according to the reciprocating motion of the other piston, and a second power generator disposed in the vicinity of the second permanent magnet. Coil for
The first magnet holder is disposed at a position opposite to the exhaust port with the other piston as a boundary in a cylinder axial direction;
The first magnet holder is connected to the one piston via a connecting member extending along the cylinder;
This is a free piston engine. In claim 3,
The free piston engine, wherein the connecting member is disposed on the opposite side of the cylinder in the radial direction with respect to an exhaust passage extending from the cylinder and connected to the exhaust port. In any one of Claims 1 thru | or 4,
The casing of the first generator and the casing of the second generator are constituted by one common casing,
Each power generating coil, each magnet holder and each permanent magnet are disposed in the common casing,
Each of the power generating coils is fixed to the common casing,
This is a free piston engine. In claim 5,
A plurality of the first power generation coils are provided at intervals in the circumferential direction of the common casing, and the first magnet holding body and the first permanent magnet correspond to the plurality of first power generation coils, respectively. A plurality of common casings are provided at intervals in the circumferential direction.
A plurality of the second power generation coils are provided at intervals in the circumferential direction of the common casing, and the second magnet holding body and the second permanent magnet correspond to the plurality of second power generation coils, respectively. A plurality of common casings are provided at intervals in the circumferential direction.
The first power generation coil and the second power generation coil are alternately arranged in the circumferential direction of the common casing,
The first magnet holder and the second magnet holder are alternately arranged in the circumferential direction of the common casing,
The first permanent magnet and the second permanent magnet are alternately arranged in the circumferential direction of the common casing,
This is a free piston engine.

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