Abstract: A heat exchanger including a heat transfer fin (1) having a heat-transfer-tube insertion hole (10) through which a heat transfer tube (40) is inserted, and a brazing material holding portion (100) provided above the heat-transfer-tube insertion hole (10) to hold a brazing material (4), wherein when the heat transfer tube (40) is inserted through the heat-transfer-tube insertion hole (10), left and right non-contact portions (15), (16) where a circumferential edge of the heat-transfer-tube insertion hole (10) and an outer circumferential surface of the heat transfer tube (40) are not in contact with each other are separately formed on an upper circumferential edge of the heat-transfer-tube insertion hole (10), and a brazing material guiding portion (100) extending toward the outer circumferential surface of the heat transfer tube (40) is formed between the left and right non-contact portions (15), (16).

Abstract: A fin-tube type of heat exchanger has: a plurality of fins laminated to one another; a housing for containing therein the fins; and a heat transfer tube penetrating the fins in a fin-laminating direction and also penetrating side plates on both sides of the housing. A heat transfer tube through hole is formed in one-side side plate of the housing by a burred hole having a tubular flange part protruded into the housing. Each fin has a brazing material insertion hole adjacent to the heat transfer tube through hole. That portion of a brazing material which protrudes from the brazing material insertion hole of the outermost fin closest to the one-side side plate part toward the one-side side plate part gets molten. The tubular flange part has a cutout part formed, at a circumferential position facing the brazing material insertion hole, by partly cutting away the tubular flange part.

Abstract: A heat transfer fin (31) made of stainless steel-based metal for a heat exchanger, has a plurality of upper stage heat-transfer-tube insertion holes (611), a plurality of lower stage heat-transfer-tube insertion holes formed (612), upper end cut portions (651) formed between the adjacent upper stage heat-transfer-tube insertion holes (611), and lower end cut portions (652) formed between the adjacent lower stage heat-transfer-tube insertion holes (612), wherein the upper end cut portions (651) are formed so as to extend from a fin upper end portion (311) beyond lower ends of the upper stage heat-transfer-tube insertion holes (611) to positions in the vicinity of upper ends of the lower stage heat-transfer-tube insertion holes (612), and the lower end cut portions (652) are formed so as to extend from a fin lower end portion (312) to positions above the lower ends of the lower stage heat-transfer-tube insertion holes (612).

Abstract: A fin-tube type of heat exchanger has: a plurality of fins laminated to one another; a housing for containing therein the fins; and a heat transfer tube penetrating the fins in a fin-laminating direction and also penetrating side plates on both sides of the housing. A heat transfer tube through hole is formed in one-side side plate of the housing by a burred hole having a tubular flange part protruded into the housing. Each fin has a brazing material insertion hole adjacent to the heat transfer tube through hole. That portion of a brazing material which protrudes from the brazing material insertion hole of the outermost fin closest to the one-side side plate part toward the one-side side plate part gets molten. The tubular flange part has a cutout part formed, at a circumferential position facing the brazing material insertion hole, by partly cutting away the tubular flange part.

Abstract: A neutral biasing mechanism in a hydrostatic continuously variable transmission includes a plurality of springs attached so as to be spanned from a pivot arm to a base. The plurality of springs bias the pivot arm such that a roller is fitted into a cam portion. A variable spring configured such that a biasing force thereof can be changed and another spring that is different from the variable spring are provided as the plurality of springs. The variable spring and the other spring are arranged at separate positions in a state where attachment positions thereof in the pivot arm and the base are separate from each other.

Abstract: A heat exchanger including a heat transfer fin (1) having a heat-transfer-tube insertion hole (10) through which a heat transfer tube (40) is inserted, and a brazing material holding portion (100) provided above the heat-transfer-tube insertion hole (10) to hold a brazing material (4), wherein when the heat transfer tube (40) is inserted through the heat-transfer-tube insertion hole (10), left and right non-contact portions (15), (16) where a circumferential edge of the heat-transfer-tube insertion hole (10) and an outer circumferential surface of the heat transfer tube (40) are not in contact with each other are separately formed on an upper circumferential edge of the heat-transfer-tube insertion hole (10), and a brazing material guiding portion (100) extending toward the outer circumferential surface of the heat transfer tube (40) is formed between the left and right non-contact portions (15), (16).

Abstract: A neutral biasing mechanism in a hydrostatic continuously variable transmission includes a plurality of springs attached so as to be spanned from a pivot arm to a base. The plurality of springs bias the pivot arm such that a roller is fitted into a cam portion. A variable spring configured such that a biasing force thereof can be changed and another spring that is different from the variable spring are provided as the plurality of springs. The variable spring and the other spring are arranged at separate positions in a state where attachment positions thereof in the pivot arm and the base are separate from each other.

Abstract: A heat transfer fin (31) made of stainless steel-based metal for a heat exchanger, has a plurality of upper stage heat-transfer-tube insertion holes (611), a plurality of lower stage heat-transfer-tube insertion holes formed (612), upper end cut portions (651) formed between the adjacent upper stage heat-transfer-tube insertion holes (611), and lower end cut portions (652) formed between the adjacent lower stage heat-transfer-tube insertion holes (612), wherein the upper end cut portions (651) are formed so as to extend from a fin upper end portion (311) beyond lower ends of the upper stage heat-transfer-tube insertion holes (611) to positions in the vicinity of upper ends of the lower stage heat-transfer-tube insertion holes (612), and the lower end cut portions (652) are formed so as to extend from a fin lower end portion (312) to positions above the lower ends of the lower stage heat-transfer-tube insertion holes (612).

Abstract: A neutral biasing mechanism in a hydrostatic continuously variable transmission includes a plurality of springs attached so as to be spanned from a pivot arm to a base. The plurality of springs bias the pivot arm such that a roller is fitted into a cam portion. A variable spring configured such that a biasing force thereof can be changed and another spring that is different from the variable spring are provided as the plurality of springs. The variable spring and the other spring are arranged at separate positions in a state where attachment positions thereof in the pivot arm and the base are separate from each other.

Abstract: A speed change operation apparatus includes a pivotal body operatively connected to a trunnion shaft to be pivotally displaced in response to an operational displacement by an operational tool, a positioning body operatively coupled with the pivotal body so as to be pivotally displaced in response to a pivotal displacement of the pivotal body, a main urging mechanism for applying an urging force to the pivotal body via the positioning body for returning the pivotal body from an operational position to the neutral position, and an auxiliary urging mechanism for applying an auxiliary urging force to the pivotal body for returning the pivotal body from the operational position to the neutral position.

Abstract: The present invention provides a tractor, comprising: a vehicle body that is supported by a plurality of wheels; a switching valve that is disposed rearwardly of a vicinity of a rear end of a driver's station floor as viewed from above; a duct connecting member that is positioned at the front end of the driver's station floor and provided with a plurality of duct connecting ports; and a plurality of metal ducts that connect the switching valve and the duct connecting member below the driver's station floor, wherein the metal ducts are positioned on a laterally outer side of a portion, that is located below the driver's station floor, of a pedal arm for an operation pedal, the pedal arm being disposed at a front portion of the driver's station floor.

Abstract: A neutral hold device for a hydrostatic continuously variable speed change device having a trunnion shaft, comprising a first member which rotates integrally with the trunnion shaft and in which a cam having a concave part is formed; a second member that pivots about a support shaft provided parallel to the trunnion shaft, and that is provided with a cam follower for engaging with the cam; a spring for urging the cam follower against the cam so that the trunnion shaft is retained in a neutral position by the cam follower being positioned in a set position of the cam by the urging of the spring; and auxiliary urging means for generating an auxiliary urging force for urging the trunnion shaft toward the neutral position while the trunnion shaft is positioned in a proximate region of the neutral position set in advance.

Abstract: A speed change operation apparatus includes a pivotal body operatively connected to a trunnion shaft to be pivotally displaced in response to an operational displacement by an operational tool, a positioning body operatively coupled with the pivotal body so as to be pivotally displaced in response to a pivotal displacement of the pivotal body, a main urging mechanism for applying an urging force to the pivotal body via the positioning body for returning the pivotal body from an operational position to the neutral position, and an auxiliary urging mechanism for applying an auxiliary urging force to the pivotal body for returning the pivotal body from the operational position to the neutral position. The returning urging force by the main urging mechanism when the trunnion shaft is located at the neutral position is stronger than the returning urging force by the main urging mechanism when the trunnion shaft is located at the operational position.

Abstract: A PTO clutch for a work vehicle and an operating structure for the PTO clutch includes: a PTO clutch having a clutch member and receiving drive power from an engine; a clutch control mechanically coupled to the clutch member for manually operating the PTO clutch via the clutch member; a PTO brake disposed downstream of the PTO clutch with respect to a direction in which power is transmitted, the PTO brake being movable to a braking position in association with a clutch disengaging operation of the clutch member; and a control retaining device for retaining the clutch control at a clutch disengaging position.

Abstract: A neutral hold device for a hydrostatic continuously variable speed change device having a trunnion shaft, comprising a first member which rotates integrally with the trunnion shaft and in which a cam having a concave part is formed; a second member that pivots about a support shaft provided parallel to the trunnion shaft, and that is provided with a cam follower for engaging with the cam; a spring for urging the cam follower against the cam so that the trunnion shaft is retained in a neutral position by the cam follower being positioned in a set position of the cam by the urging of the spring; and auxiliary urging means for generating an auxiliary urging force for urging the trunnion shaft toward the neutral position while the trunnion shaft is positioned in a proximate region of the neutral position set in advance.

Abstract: A working vehicle with a speed maintaining apparatus having a plurality of wheels including at least one driven wheel; a vehicle body supported by the plurality of wheels; an engine supported by the vehicle body; a stepless transmission driven by the engine and capable of changing speed of power to the driven wheel; a neutral return device for biasing the stepless transmission toward a neutral position; a change speed pedal operatively connected to the stepless transmission; a speed maintaining device for maintaining the stepless transmission in a desired speed position; a speed setting lever movable to a retreat position and to positions in a forward speed range for setting the stepless transmission to the desired speed position in which the stepless transmission is maintained by the speed maintaining device; a relay rocking element connected to the stepless transmission through an auxiliary rocking element pivotable relative to the relay rocking element; and a control member provided in the speed maintainin

Abstract: The present invention provides a tractor, comprising: a vehicle body that is supported by a plurality of wheels; a switching valve that is disposed rearwardly of a vicinity of a rear end of a driver's station floor as viewed from above; a duct connecting member that is positioned at the front end of the driver's station floor and provided with a plurality of duct connecting ports; and a plurality of metal ducts that connect the switching valve and the duct connecting member below the driver's station floor, wherein the metal ducts are positioned on a laterally outer side of a portion, that is located below the driver's station floor, of a pedal arm for an operation pedal, the pedal arm being disposed at a front portion of the driver's station floor.

Abstract: A tractor with a PTO apparatus, comprises: a plurality of wheels; a vehicle body supported by the plurality of wheels; an engine supported on the vehicle body; a rear PTO shaft disposed at a rear of the vehicle body for transmitting power from the engine; a mid-PTO shaft disposed under the vehicle body for transmitting power from the engine; a PTO mode selecting device having a first position for transmitting power only to the rear PTO shaft, a second position for transmitting power to both the rear PTO shaft and said mid-PTO shaft, and a third position for transmitting power only to said mid-PTO shaft; a PTO clutch disposed on a transmission line upstream of said PTO mode selecting device and switchable between an engaged position and a disengaged position; and a restricting mechanism for preventing a change operation of said PTO mode selecting device when said PTO clutch is in the engaged position, and permitting the change operation of said PTO mode selecting device when said PTO clutch is in the disengage

Abstract: A transmission system for transmitting power through a traveling transmission line and also through a PTO transmission line is disclosed. The system includes a clutch housing and a base transmission case connected via a housing frame. The base transmission case includes a front end opening and a rear end opening. A differential case is connected to the rear end opening. The front end opening is selectively connected with either a gear change speed case having a gear change speed mechanism or an HST case having an HST mechanism. When the gear change speed mechanism is selectively used, a PTO power output portion communicates with the PTO transmission line and a traveling power output portion communicates with the traveling transmission line. When the HST mechanism is selectively used, a pump shaft communicates with the PTO transmission line and a motor shaft communicates with the traveling transmission line.

Abstract: A PTO clutch for a work vehicle and an operating structure for the PTO clutch includes: a PTO clutch having a clutch member and receiving drive power from an engine; a clutch control mechanically coupled to the clutch member for manually operating the PTO clutch via the clutch member; a PTO brake disposed downstream of the PTO clutch with respect to a direction in which power is transmitted, the PTO brake being movable to a braking position in association with a clutch disengaging operation of the clutch member; and a control retaining device for retaining the clutch control at a clutch disengaging position.