JPH0663876U - air compressor - Google Patents

Abstract

(57) [Summary] [Purpose] In an air compressor, improve assembly and share parts. In an air compressor in which a low pressure cylinder 2, a medium pressure cylinder 3 and a high pressure cylinder 4 are radially arranged, a first crank pin portion 93 located on the base end side of a cantilevered crank shaft 9 is provided. High-voltage connecting rod 8,
The second crank pin portion 94, which is located closer to the tip than the first crank pin portion 93 and has a smaller diameter, is provided with the medium pressure connecting rod 7, which is located closer to the tip than the second crank pin portion 7 and has a smaller diameter. While the low pressure connecting rods 6 are attached to the third crank pin portions 95 of the above, the cylinder receiving hole 16 and the cylinder receiving hole 16 are formed in the cylinder fastening surface 11.
Notch 1 that continuously extends to one side of the diametrically outward side
7 and the flange portion 4 of the high pressure cylinder 8
1 is fastened with the spacer 20 interposed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a multi-stage air compressor having a cantilevered crankshaft.

[0002]

[Prior art]

 When developing an air compressor, especially a large-capacity air compressor, it is necessary to consider that it can be provided with high performance, a simple structure, and a low price. Of these requirements, it is well known that the three-stage compression method is suitable especially in terms of performance.

Further, when adopting such a three-stage compression system, as one method for simplifying the structure and lowering the cost, for example, a cantilever support system is used for the crankshaft and the overhang portion is It is conceivable to form the plurality of crank pin portions such that the diameters thereof gradually increase from the tip end side toward the base end side. In this way, even if the large end of each connecting rod has an annular integral structure, when it is assembled to the crankshaft, they are passed through from the crank pin part side near the tip, which has a small diameter dimension, and then placed near the base end. Since it can be assembled by sequentially moving it to a large-diameter crank pin part, it is not necessary to use a lot bolt to fasten this large end part in half as in the conventional general structure. The cost can be reduced by simplifying and improving the assembling ability or reducing the number of parts. Also, by adopting this method, it is possible to change the stroke for each stage, so it can be expected that the compression efficiency will be improved, and the diameter of the third stage piston that will be loaded will be thicker. It is also effective in terms of strength.

As described above, in order to improve the performance, simplify the structure, or reduce the cost of the air compressor, the crankshaft is cantilevered and has a generally bamboo-like shape in which the diameter dimension becomes smaller toward the tip end side. It can be said that doing is one of the effective means.

On the other hand, in a multi-stage air compressor, usually, a cylinder block and a cylinder are separately formed, and a cylindrical cylinder is formed in a circular cylinder receiving hole radially arranged around the crank chamber of the cylinder block. The spigot fitting part formed at one end is tightly fitted and fastened. In this case, the diameter of the spigot fitting part of the cylinder is the same as the outer dimension of the peripheral wall of the cylinder because the appropriate size of the flange adjacent to the spigot fitting part is set corresponding to the cylinder diameter. It is customary to set the value close to. Further, when the above-mentioned integral type connecting rod is adopted, this cylinder receiving hole functions as a space for inserting the connecting rod when the connecting rod is assembled to the crankshaft.

[0006]

[Problems to be solved by the device]

 By the way, when such a cantilevered and generally bamboo-shaped crankshaft is adopted, a cylinder with a larger compression reaction force is closer to the base end of the crankshaft in order to improve the stress performance of the crankshaft. It is required to have an arrangement structure that corresponds to the pin portion.For example, in the case of a three-stage compression type, the high pressure cylinder that is the final compression stage is assigned to the crank pin portion from the most proximal end of the crankshaft. Will be made.

However, the diameter of this last stage cylinder is the smallest as compared with the other cylinders, and therefore the diameter of the cylinder receiving hole of the cylinder block to which it is attached is also the smallest. On the other hand, the connecting rod provided in the cylinder at the final stage corresponds to the crank pin portion that has the largest diameter at the most proximal end of the crankshaft, so the diameter of the large end is different from that of the other. It is the largest in comparison.

As a result, when the connecting rod is inserted into the crank chamber through the cylinder receiving hole when the connecting rod is attached to the crankshaft, the diameter of the connecting rod large end may be changed depending on the case. It may be larger than the inner diameter of the product and it may not be assembled.

In this case, it is conceivable that the diameter of the cylinder receiving hole is set to a large size in accordance with the size of the large end portion of the connecting rod regardless of the cylinder diameter to enable the insertion / removal. In this case, the diameter of the spigot fitting part of the cylinder increases as the diameter of the cylinder receiving hole increases, which in turn causes the flange part to become unnecessarily large relative to the cylinder diameter, resulting in increased weight. At the same time, the cylinder and cylinder block are exclusive products that can only be used for that model, which may contribute to cost increase, and in any case, it is not a good idea.

Therefore, the present invention has been made as an attempt to provide an air compressor capable of simplifying the structure and sharing parts while retaining the advantages unique to a cantilevered crankshaft. .

[0011]

[Means for Solving the Problems]

 In the present invention, as a specific means for solving such a problem, a low pressure cylinder, a medium pressure cylinder, and a high pressure cylinder are attached to a plurality of cylinder fastening surfaces formed in a radial pattern around the crank chamber of a cylinder block. Are fixed to the cylinder fastening surface by abutting and fastening the flange portions formed on the base end portions thereof, respectively, and at the same time, the pistons slidably fitted in the respective cylinders and the crank and Crankshafts located inside the room are connected via connecting rods respectively, and after the intake air is compressed by the low pressure cylinder for the first stage, it is compressed for the second stage by the medium pressure cylinder and then for the high pressure. In an air compressor in which a third-stage compression is performed by a cylinder, the crankshaft is supported by a bearing on the cylinder block side in a cantilevered manner. The crank pin portion is located in the rank chamber, the crank pin portion is located near the bearing and the high pressure connecting rod is attached, and the crank pin portion is located closer to the tip than the first crank pin portion and is for the medium pressure connecting rod. The second crank pin portion, which is attached to the second crank pin portion and has a diameter smaller than that of the first crank pin portion, and the low pressure connecting rod is attached to the tip end side of the second crank pin portion. And a third crankpin portion having a smaller diameter than that of the cylinder block. Further, a cylinder fastening surface of the cylinder block corresponding to the high pressure cylinder penetrates a side wall of the cylinder block and the high pressure cylinder. The cylinder receiving hole that allows the spigot fitting part formed at the end of the And a notch having a size that allows the passage of the large end of the high-pressure connecting rod between the cylinder receiving hole and the cylinder receiving hole, and the high-pressure cylinder has a flange portion. Is characterized in that it is fastened and fixed to the cylinder fastening surface with a spacer having a shape capable of closing the notch in the state of abutting against the cylinder fastening surface. I am trying.

[0012]

[Action]

 According to the present invention, by adopting such a configuration, the large end of the high-pressure connecting rod attached to the largest diameter first crank pin portion corresponds to the diameter of the first crank pin portion and is the largest of the connecting rods. On the other hand, the cylinder receiving hole for the high-pressure cylinder, which becomes a space for inserting the high-pressure connecting rod into the crank shaft while it becomes larger, corresponds to the fact that the high-pressure cylinder has the smallest diameter compared to other cylinders. Is the smallest diameter. Therefore, the diameter of the large end of the high-pressure connecting rod may become larger than that of the cylinder receiving hole, and its insertion may be blocked. Since the notch formed so as to communicate with the cylinder and extend in the radial direction together with the cylinder receiving hole forms a large end portion insertion space having a length larger than the diameter dimension of the cylinder receiving hole, this insertion space It is possible to insert the large end into the cylinder block and assemble it to the crankshaft.

Further, as described above, by forming a notch in a part of the cylinder receiving hole formed on the cylinder block side, the assembly of the connecting rod can be carried out without unnecessary change of shape on the cylinder side. Since it is made possible if possible, the cylinder can be directly applied to not only the model but also other models, and the cylinder can be shared among a plurality of models. Further, a spacer, which is a separate member, is interposed between the cylinder tightening surface of the cylinder block and the flange portion of the cylinder, and the notch is covered by the spacer to improve the sealing performance between the cylinder block and the cylinder. Since the cylinder block is secured, it is possible to apply the cylinder block to multiple models and to share the cylinder block by appropriately setting the shapes of the notch and the spacer.

[0014]

[Effect of device]

 Therefore, according to the air compressor of the present invention, the large end of the high-pressure connecting rod corresponding to the first crank pin portion on the base end side of the crankshaft has the largest diameter among the connecting rods. On the other hand, in a multi-stage air compressor equipped with a cantilevered crankshaft, which has a reciprocal relationship that the cylinder receiving hole corresponding to the high pressure cylinder, which is the insertion space of the large end, has the smallest diameter among the cylinder receiving holes. In spite of this, the effect that is unique to the cantilevered crankshaft, that is, the structure is simple and the assembling of the connecting rod to the crankshaft is also good, while sharing a cylinder or cylinder block. However, it has a practical effect that it can contribute to cost reduction.

[0015]

【Example】

 Hereinafter, the air compressor of the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings. An air compressor Z according to the embodiment of the present invention is shown in FIGS. The air compressor Z is an air-cooled three-stage compression type air compressor, and in each of the drawings, reference numeral 1 is a cylinder block having a crank chamber 1a formed at one axial end thereof. Inside the cylinder block 1, journal portions 91 and 92 are formed at one end and an intermediate portion thereof, respectively, and at the other end side thereof, a first crank pin portion 93, a second crank pin portion 94 and a third crank pin portion 95. A crankshaft 9 formed by continuously forming the above-mentioned parts locates each of the pin parts 93, 94, 95 in the crank chamber 1a, and the journal part 91 and the journal part 92 together with the bearings 25, 26 of the cylinder block 1. It is placed in a cantilevered state in which each is rotatably supported. The crankshaft 9 is rotatably driven by a motor (not shown) via a pulley 31 attached to one end of the crankshaft 9. In FIG. 2, reference numeral 32 is a fan attached to the pulley 31.

Further, in consideration of stress characteristics, the crank pin portions 93, 94, 95 of the crank shaft 9 extend from the first crank pin portion 93 near the support portion to the third crank pin portion 95 on the tip side. The diameter is gradually reduced. Of the crank pin portions 93 to 95, the large diameter first crank pin portion 93 has the large end portion 8a of the high-pressure connecting rod 8 described later, and the medium diameter second crank pin portion 94 has the large end portion 8a. The large end portion 7a of the medium pressure connecting rod 7 is attached to the third crank pin portion 95 having the smallest diameter, and the large end portions 6a of the pair of low pressure connecting rods 6 are attached to the third crank pin portion 95, respectively. In FIG. 2, reference numeral 34 is a pump drive shaft, and the pump drive shaft 34 is rotatable with a predetermined eccentric amount to the tip end portion of the crankshaft 9, that is, the end portion of the third crank pin portion 95. The crankshaft 9 is rotated with the rotation of the crankshaft 9 to drive the lubricating oil pump 33. Also, in FIG. 2, reference numerals 23 and 24 are balance weights.

On the other hand, on the outer peripheral wall of the crank chamber 1a of the cylinder block 1, four cylinder fastening surfaces 11, 11, 12, 13 are formed radially from the axial center of the crank shaft 9. Of the cylinder fastening surfaces 11 to 13, the two cylinder fastening surfaces 11, 11 located on the upper surface side of the cylinder block 1 are for attaching the largest diameter low pressure cylinders 2, 2. And a cylinder receiving hole 14 for fitting the end portion of the low pressure cylinder 2 with the spigot. A cylinder receiving hole 15 is formed in the cylinder fastening surface 12 formed on one side wall of the cylinder block 1 so that one end of the medium-pressure medium-pressure cylinder 3 can be fitted in the spigot. Further, the cylinder fastening surface 13 formed on the other side wall of the cylinder block 1 is provided with a cylinder receiving hole 16 for fitting the spigot fitting portion 42 formed at the end of the high pressure cylinder 4 having the smallest diameter. Has been formed.

Each of the connecting rods 6 to 8 has an annularly-integrated large end portion 6a to 8a as shown in FIG. 1, and the crank chamber 1 is passed through the corresponding cylinder receiving holes 14 to 16, respectively.
While being inserted into and removed from a, it is attached to the crank shaft 9 in order from the large-diameter high-pressure connecting rod 8 side (the reverse is the case when removing). That is, in the state before mounting the pump drive shaft 34, the large ends 6a to 8a of the low pressure connecting rods 6 to 8 are inserted into the crank chamber 1a from the corresponding cylinder receiving holes 14 to 16, respectively. Then, for example, when the high-pressure connecting rod 8 is attached, first, the high-pressure connecting rod 8 is slightly inclined in the axial direction of the crankshaft 9 and the shaft hole 8b (FIG. (See), the end of the third crank pin portion 95 is exposed, and then the third crank pin portion 95 is moved to the side of the first crank pin portion 93 and fitted therein. The same applies to the other connecting rods 6 and 7.

In this way, the crankshaft 9 is formed in a cantilevered, generally bamboo-like shape, and the large ends 6a to 8a of the connecting rods 6 to 8 are integrally formed into an annular shape, and the large ends 6a to 8a are formed from the ends of the crankshaft 9. As described above, it is possible to simplify the structure or improve the workability of assembling by sequentially fitting.

By the way, when such a crank structure is adopted, a problem is the assembling property of the high pressure connecting rod 8. That is, in the high pressure cylinder 4 portion, the large end 8a of the high pressure connecting rod 8 is fitted to the first crank pin portion 93 having the largest diameter among the crank pin portions of the crank shaft 9. Therefore, while the diameter dimension is the largest, the cylinder receiving hole 16 that serves as a space for inserting and removing the large end 8a of the high pressure connecting rod 8 has the smallest diameter of the high pressure cylinder 4 among the cylinders. Correspondingly, it has the smallest diameter. Therefore, depending on various conditions such as the capacity and compression ratio of the air compressor, the outer shape of the large end portion 8a of the high pressure connecting rod 8 may be larger than the inner diameter of the cylinder receiving hole 16, and in such a case, As a result, the high-pressure cylinder 8 cannot be assembled, and the above-described advantages of the cantilevered crankshaft cannot be utilized. Also, in order to be able to attach the high-pressure connecting rod 8, if the diameter of the cylinder receiving hole 16 is unnecessarily increased to a predetermined dimension or more determined according to the cylinder diameter, the size of the cylinder will be large. As mentioned above, it is not a good idea because it causes weight increase.

However, in this embodiment, the diameter of the cylinder receiving hole 16 is continuously maintained on one side of the cylinder receiving hole 16 while maintaining the predetermined size determined by the cylinder diameter. A notch portion 17 extending in the radial direction is formed, and the cylinder receiving hole 16 and the notch portion 17 ensure an insertion space for the large end portion 8a of the high pressure connecting rod 8. Therefore, the high pressure connecting rod 8 is introduced into the crank chamber 1a through the cylinder receiving hole 16 portion without changing the size of the spigot fitting portion 42 of the high pressure cylinder 4 or the size of the cylinder receiving hole 16 of the cylinder block 1. It can be inserted and fitted into the first crank pin portion 93.

Further, in this case, in order to secure the sealing property of the cutout portion 17 when the high pressure cylinder 4 is mounted on the cylinder fastening surface 13, the flange of the high pressure cylinder 4 and the cylinder fastening surface 13 is secured. A spacer 20 having a size capable of covering the cutout portion 17 and a pair of packings 21, 21 positioned on both sides thereof are interposed between the portion 41 and the portion 41.

By doing so, the high pressure cylinder 4 can be directly applied to other models as long as the diameter dimension thereof is matched, and also in the cylinder block 1, the notch portion is formed by interposing the spacer 20. It can be applied as it is to a model that needs to form 17 or a model that does not, and as a result, the high pressure cylinder 4 and the cylinder block 1 can be shared, and as a whole, the air compressor as a whole can be constructed. It can contribute to cost reduction.

When the high-pressure connecting rod 8 is attached to the crankshaft 9 side, the shaft hole 8b is oriented horizontally as shown by the solid line in FIG. The shaft hole 8b is rotated 90 ° so that the shaft hole 8b is oriented in the vertical direction as shown by the chain line in FIG.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional front view of an air compressor according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along the line II-II in FIG.

3 is an exploded perspective view of a main part of a high pressure part of the air compressor shown in FIG.

[Explanation of symbols]

1 is a cylinder block, 2 is a low pressure cylinder, 3 is a medium pressure cylinder, 4 is a high pressure cylinder, 5 is a piston, 6 is a low pressure connecting rod, 7 is a medium pressure connecting rod, 8 is a high pressure connecting rod, 9 is a crankshaft, 11 to 13 are cylinder fastening surfaces, 14 to 16 are cylinder receiving holes, 17 is a notch, 20 is a spacer, 21 is packing, 23 and 2
4 is a balance weight, 25 to 27 are bearings, 31 is a pulley, 32 is a fan, 33 is a lubricating oil pump, 34 is a pump drive shaft, 41 is a flange part, 42 is a spigot fitting part,
Reference numerals 91 and 92 are journal portions, and reference numerals 93 to 95 are crankpin portions.

Claims (1)

[Scope of utility model registration request] 1. A plurality of cylinder fastening surfaces that are formed radially in sequence around the crank chamber of a cylinder block,
The low pressure cylinder, the medium pressure cylinder, and the high pressure cylinder are fixed by abutting and fastening the flange portions formed at their base ends to the cylinder fastening surface, respectively, and slidably on the respective cylinders. The piston to be fitted and the crankshaft arranged in the crank chamber are connected through connecting rods, respectively, and the intake air is compressed in the first stage by the low pressure cylinder, and then is compressed by the medium pressure cylinder in the second stage. An air compressor in which the third compression is performed by the high pressure cylinder and the crankshaft is cantilevered by a bearing on the cylinder block side. A first crank pin portion, which is disposed in a room, has a crank pin portion located near the bearing and to which a high-pressure connecting rod is attached, and the first crank pin portion. A second crank pin portion having a diameter smaller than that of the first crank pin portion, the medium pressure connecting rod being mounted at a position closer to the tip than the first crank pin portion;
A low pressure connecting rod is mounted on the tip side of the second crank pin portion, and is formed by a third crank pin portion having a diameter smaller than that of the second crank pin portion. A cylinder receiving hole for penetrating a side wall of the cylinder block and allowing a spigot fitting portion formed at an end portion of the high pressure cylinder to be tightly fitted to the cylinder fastening surface corresponding to the high pressure cylinder, and the cylinder receiving hole. A notch which is continuous with one side of the hole and extends outward in the radial direction thereof and is formed between the cylinder receiving hole and a size large enough to allow passage of the large end of the high-pressure connecting rod. In addition, the high-pressure cylinder has a flange portion with a spacer having a shape capable of closing the cutout portion in a state of abutting against the cylinder fastening surface. Air compressor, characterized by being fastening fixed to da fastening surface.