A hook-type standard penetration test automatic drop hammer device

Abstract

The utility model discloses a kind of hook type standard penetration test automatic drop hammer device, including guide rod, guide rod is divided into two sections, lower section is thin equal-diameter rod, upper section includes thick equal-diameter rod and the smooth transition portion gradually changed from thin equal-diameter rod to thick equal-diameter rod;Guide rod is installed with lifting and drawing snap ring, lifting and drawing snap ring upper end port inner diameter is not less than thick equal-diameter rod diameter, lower end port inner diameter is equal to thin equal-diameter rod diameter, lifting and drawing snap ring inside is equipped with multiple deslagging grooves;Two through grooves are symmetrically equipped in lifting and drawing snap ring side wall, respectively hinged with hook in groove, the hinged shaft of hook is located in hook middle part, hook upper part extends to thin equal-diameter rod inwards, hook lower part has hook head and extends outwards, hinged place is also equipped with torsion spring.This application has adopted hook type automatic unhooking technology, not only can realize the function of automatic drop hammer, and simple and reliable structure, not easy to jam.

Description

Technical Field

[0001] This application relates to the field of geotechnical engineering investigation technology, and in particular to an automatic drop hammer device for in-situ standard penetration testing using a hook. Background Technology

[0002] The Standard Penetration Test (SPT) is a method for determining the bearing capacity of sandy or cohesive soil foundations in the field. The test uses a specific penetrator, typically a split-tube penetrator, which is driven into the soil layer by a hammer of a certain mass (63.5 kg) dropped freely from a certain height (76 cm). The penetration resistance of the penetrator is represented by the number of hammer blows (N value) required to penetrate 30 cm. This N value is an important indicator for evaluating the soil density and engineering properties.

[0003] Existing automatic drop hammer devices for standard penetration tests are all ball-clamp type. During field construction, the device frequently fails to engage the drop hammer. This is mainly because this method requires high precision; even slight debris inside the mechanism can affect proper engagement, and sand is sometimes unavoidable on-site. In such cases, the usual methods are to wash away the sand with water or manually press the automatic drop hammer device into place, causing inconvenience and posing safety hazards. Utility Model Content

[0004] The technical problem to be solved by this application is to provide an automatic drop hammer device for hook-type standard penetration test that is simple in structure, convenient and reliable.

[0005] To address the aforementioned problems, this application provides an automatic drop hammer device for a hook-type standard penetration test, comprising a guide rod divided into upper and lower sections. The lower section is a thin, equal-diameter rod, while the upper section includes a thick, equal-diameter rod and a smooth transition section that gradually transitions from the thin, equal-diameter rod to the thick, equal-diameter rod. A lifting ring is installed on the guide rod. The inner diameter of the upper end of the lifting ring is not less than the diameter of the thick, equal-diameter rod, and the inner diameter of the lower end is equal to the diameter of the thin, equal-diameter rod. Multiple slag discharge grooves are provided inside the lifting ring. Two through grooves are symmetrically provided on the side wall of the lifting ring, and hooks are hinged to the middle of the grooves. The hinge axis of the hook is located in the middle of the hook. The upper part of the hook extends inward to the thin, equal-diameter rod, and the lower part of the hook extends outward with a hook head. A torsion spring is also provided at the hinge, causing the upper part of the hook to have a tendency to rotate inward.

[0006] Furthermore, the upper and lower sections of the guide rod are detachable and connected by a threaded connection.

[0007] Furthermore, the through groove on the lifting ring is equipped with a stop.

[0008] Furthermore, a through-hole hammer is fitted below the guide rod, and a pad is fixedly installed below the through-hole hammer.

[0009] Furthermore, the bottom of the pad is fixedly connected to parts such as drill rods.

[0010] Furthermore, a traction ring is fixed on the lifting ring.

[0011] This application has the following advantages compared with the prior art:

[0012] Unlike existing ball-clip type drop hammer devices, this application adopts a more reliable hook type, which not only realizes the function of automatic drop hammer, but also has a simple structure and is not easy to jam. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this application;

[0014] Figure 2 This is a schematic diagram of the extraction ring structure of this application;

[0015] Figure 3 This is a top view of the indexing ring of this application;

[0016] Figure 4 This is a cross-sectional view of the drawing ring of this application;

[0017] Figure 5 This is a cross-sectional schematic diagram of the hook of this application catching the annular lifting surface of the hammer.

[0018] Figure 6 This is a cross-sectional schematic diagram of the annular lifting surface of the hook release hammer in this application.

[0019] In the diagram: 1-Guide rod, 2-Lifting ring, 3-Hook, 4-Torsion spring, 5-Stop, 6-Thrust hammer, 7-Padded block, 8-Traction ring, 9-Slag discharge trough, 10-Annular lifting surface. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to help understand the content of the present invention.

[0021] refer to Figure 1-6 This application provides an automatic drop hammer device for a hook-type standard penetration test, including a guide rod 1. The guide rod 1 is divided into upper and lower sections. The lower section is a thin equal-diameter rod, and the upper section includes a thick equal-diameter rod and a smooth transition section that gradually changes from a thin equal-diameter rod to a thick equal-diameter rod. A lifting ring 2 is installed on the guide rod 1. The inner diameter of the upper port of the lifting ring 2 is not less than the diameter of the thick equal-diameter rod, and the inner diameter of the lower port is equal to the diameter of the thin equal-diameter rod. The lifting ring 2 is provided with multiple slag discharge grooves 9, which are used to discharge sand and soil if it enters the lifting ring 2, thus preventing jamming.

[0022] The lifting ring 2 has two through slots symmetrically arranged on its side wall. Hooks 3 are hinged in the middle of the slots respectively. The hinge shaft on the lifting ring 2 is located on the outside of the side wall of the lifting ring 2. The hinge shaft of the hook 3 is located in the middle of the hook 3. The upper part of the hook 3 extends inward to the thin equal diameter rod. The lower part of the hook 3 extends outward with a hook head. A torsion spring 4 is also provided at the hinge, so that the upper part of the hook 3 has a tendency to rotate inward. A through hammer 6 is sleeved below the guide rod 1. A pad block 7 is fixedly installed below the through hammer 6.

[0023] As a preferred embodiment, for ease of installation and use, the upper and lower sections of the guide rod 1 are detachably connected by a threaded connection.

[0024] As a preferred embodiment, the through groove on the lifting ring 2 is provided with a stop 5, which is used to block the upper part of the hook 3 when the mandrel 6 is disengaged and the lifting ring 2 is in the thin equal diameter rod, thereby reducing the wear on the upper part of the hook 3.

[0025] The usage process and principle of this device:

[0026] When conducting the standard penetration test, first install the device in place, connect the traction ring 8 to the winch equipment using a steel wire rope, and control the lifting ring 2 to fall. Since the lifting ring 2 itself has a certain mass, when the lower part of the hook 3 contacts the annular lifting surface 10 of the hammer 6, it can overcome the elastic force of the torsion spring 4 and cause the hook head of the hook 3 to fall below the annular lifting surface 10. After falling in, the elastic force causes the hook head to extend and hook the annular lifting surface 10.

[0027] During the upward lifting process, since the hinge shaft and the force-bearing part of the hook head are roughly on the same vertical line, the hook 3 will not rotate and cause it to disengage. When it is lifted to the smooth transition part that turns into a coarse equal diameter rod (i.e., the lifting height of the hammer 6 is 76cm), the upper part of the hook 3 is pushed outward by the guide rod 1, causing the hook 3 to rotate and the hook head to retract into the lifting retainer 2, thereby causing the hammer 6 to disengage and fall freely. Repeating the above process can complete the standard penetration test.

[0028] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the structure and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. An automatic drop hammer device for a hook-type standard penetration test, characterized in that, The guide rod (1) is divided into two sections, the lower section being a thin equal-diameter rod and the upper section including a thick equal-diameter rod and a smooth transition section that gradually changes from a thin equal-diameter rod to a thick equal-diameter rod. A lifting ring (2) is installed on the guide rod (1). The inner diameter of the upper port of the lifting ring (2) is not less than the diameter of the thick equal-diameter rod, and the inner diameter of the lower port is equal to the diameter of the thin equal-diameter rod. Multiple slag discharge grooves (9) are provided inside the lifting ring (2). Two through grooves are symmetrically provided on the side wall of the lifting ring (2). Hooks (3) are hinged in the grooves respectively. The hinge axis of the hook (3) is located in the middle of the hook. The upper part of the hook (3) extends inward to the thin equal-diameter rod, and the lower part of the hook (3) extends outward with a hook head. A torsion spring (4) is also provided at the hinge, so that the upper part of the hook (3) has a tendency to rotate inward.

2. The automatic drop hammer device for hook-type standard penetration test according to claim 1, characterized in that, The upper and lower sections of the guide rod (1) are detachable and connected by a threaded connection.

3. The automatic drop hammer device for hook-type standard penetration test according to claim 1, characterized in that, The through groove on the lifting ring (2) is provided with a stop (5).

4. The automatic drop hammer device for hook-type standard penetration test according to claim 1, characterized in that, A through-hole hammer (6) is sleeved below the guide rod (1), and a pad (7) is fixedly installed below the through-hole hammer (6).

5. The automatic drop hammer device for a hook-type standard penetration test according to claim 4, characterized in that, The bottom of the pad (7) is fixedly connected to a drill rod.

6. The automatic drop hammer device for hook-type standard penetration test according to claim 1, characterized in that, A traction ring (8) is fixed on the lifting ring (2).

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